There are 105 Secrets in Assassin’s Creed IV Black Flag Resynced. For trophies & achievements most of them are not needed, you only need a few specific ones that give Art Pieces, Swords, Pistols.
Secrets come in 3 forms: 
Treasure Maps, 
Bottled Letters, and 
Special Chests.
Secrets (Special Chests) are not to be confused with 
Regular Chests. The difference is that Special Chests have a bigger icon on the map and give items. Regular Chests have a smaller icon and only give money. The game classifies them as different collectible types entirely when scrolling over locations, despite both being chests you open.
On the map’s collectible tracker the “Special Chests” will count as “Secrets”, and the “Money Chests” count as “Chests”. This guide here covers specifically what counts as Secrets. For regular Chests refer to the Chests Guide.
You can still find everything after the story in free-roam, nothing is missable.
Collectibles Overview:
Dry Tortuga Region
Cape Bonavista
#1 – Letter: “The Observatorie”
On the north-east side of the island, near the river.
#2 – Treasure Map from Cape Bonavista
On the corpse at the cave entrance.
Solution: Cape Bonavista (146, 587 – from the beach in the south of Cape Bonavista you enter a big cave, the treasure is at the end of the cave in a small puddle of water
#3 – Diamond Trinket (Common Trinket)
At the bottom of the river near the viewpoint.
Havana
#4 – Treasure Map from Havana
On a corpse in the canal.
Solution: Havana (213, 564 – At the southern shore of Havana below a tower
#5 – Exotic Sea Shells (Rare Trinket)
In the small area between 2 buildings.
#6 – Brown Cloak (Common Outfit)
In a small building in the governors fenced off area.
#7 – “Cortez and La Malinche” from The History of Tlaxcala (Manuscript)
Inside a small fenced alleyway.
#8 – “Tabulae Rudolphinae” (Manuscript)
In a small courtyard, guarded by enemies.
#9 – “Voynich Manuscript” – Folio 34v (Manuscript)
In the northern tower of the fort in the north-east. You can access it by going to the top of the tower and dropping down some scaffolding along the wall to go through the window.
#10 – Spanish Cup-hilt Rapiers (Common Weapon)
In the middle of the fort near the warehouse.
Matanzas
#11 – Letter: “On Leaving Home”
Pick up the bottle in the sand on the west end of the beach.
#12 – Bronze Wheel (Common Wheel)
Open the chest on the second floor of the manor.
Florida
#13 – Privateer’s Cutlass (Common Cutlass – 25 Damage, 2 Takedowns)
Open the chest in the south of the island.
#14 – Letter: “Reste and Repaste”
Pick up the bottle in the sand in the north of the island, next to a dead body.
Salt Key Bank
#15 – Gold Earring (Common Trinket)
Underwater in the small pond in the south.
#16 – Letter: “On the Place of My Birthe”
In the sand at a small camp in the south.
San Ignacio Wreck – accessible after Sequence 06 – Mission 01: Diving for Medicines
#17 – Ship Upgrade Plan: Hull Armor Ultimate Plan
From one of the underwater chests.
Eleuthera Region
Andreas Island
#18 – “Aberdeen Bestiary” (Manuscript)
Underneath one of the buildings. You can access it by breaking the small crates.
#19 – Letter: “A Curiouse Incident At Sea”
On the sand, next to a tree.
#20 – Treasure Map from Abaco Island
On a corpse near the shipwreck debris.
Nassau
#21 – “Voynich Manuscript” – Folio 35r (Manuscript)
Underwater by the shipwreck debris.
#22 – “Introductio Geographica” (Manuscript)
On the 2nd floor of the manor.
#23 – “Epistola de Magnete” (Manuscript)
Under a small awning.
#24 – “Vertumnus, a Portrait of Today” (Manuscript)
Inside a tent guarded by enemies.
#25 – Columbus Map (Manuscript)
Under a small awning near the edge of the fort.
Abaco Island
#26 – Letter: “Peter Beckford the Elder”
In the sand by the crashed boat.
#27 – Treasure Map from Abaco Island
On a corpse against one of the trees.
Solution: Salt Lagoon (719, 607 – in front of the tallest rock at the beach, in the sand
#28 – Tattered Sails (Common Sails)
Underwater inside the shipwreck.
Cat Island
#29 – Crimson Sails (Common Sails)
On the balcony in the manor.
Gibara Region
Jiguey
#30 – Letter: “My Deepening Predicament”
In the sand on the beach.
#31 – Cannon-Barrel Pistols (Rare Pistol)
Loot or pickpocket the key from the enemy by the campfire.
Salt Lagoon
#32 – Treasure Map from Salt Lagoon
On a corpse along the beach.
Black Island
#33 – The Black Ship’s Sails (Rare Sails)
Under a small awning on a hill.
#34 – Captain Morgan’s Redingote (Legendary Outfit)
Along the edge of the cliff.
#35 – Captain Morgan’s Pistols (Rare Pistol)
Underwater near the shipwreck debris.
Crooked Island
#36 – Letter: “My First Reverie”
On a section of the beach.
#37 – German Rapiers (Common Sword)
Along the rocks of the cliff.
Mariguana Island
#38 – “Solaris” from “Mundus Subterraneus” (Manuscript)
Inside of a small cave covered by vines.
#39 – Treasure Map from Mariguana Island
In the same area as the previous collectible.
Solution: Andreas Island (544, 693 – on a small island in the south of Andreas Island
Great Inagua
#40 – Treasure Map from Great Inagua
Inside a small cave on the west. You can climb across the branches to access the cave.
Solution: Nassau (586, 755 – on the west edge of Nassau town, directly below a long cliff that sticks out the side of the mountain
#41 – Captain’s Wheellock Pistols (Rare Pistol)
Underwater near the viewpoint.
#42 – Chalice (Art Piece)
Inside the building by the water wheel.
#43 – The Ezio’s Sails (Legendary Sails)
In the treasury underneath the manor.
#44 – The Altair’s Sails (Legendary Sails)
At the end of the woods near the Mayan Stelae.
#45 – Letter: “On My Name and Origin”
On the southern beach, in the sand.
Antocha Wreck – accessible after Sequence 06 – Mission 01: Diving for Medicines
#46 – Ship Upgrade Plan: Mortars Ultimate Plan
From one of the underwater chests.
Punta Guarico Region
Tortuga
#47 – Treasure Map from Tortuga
Loot the skeleton next to the rowboat.
Solution: Matanzas (312, 617 – in the south-east corner of Matanzas, to the left of the Mayan Stelae behind the waterfall.
#48 – Manuscript “Crónicas dos Feitos de Guiné”
It’s on the left side of the house.
#49 – Letter “What the Voices Saide”
It’s below a palm, on the north side of the map.
Caracol
#50 – Ship Vanity Item: Flower Wheel
Go behind the buildings and to the right, jump down into the water.
#51 – Letter “My Searche”
From the previous secret, just get out of the water. It’s right on the beach.
Petite Caverne
#52 – Weathered Map Piece
To open the chest, you need to get a key. Loot it from the officer in front of the chest. This will also unlock 
Among Thieves if you do not have it already.
#53 – Treasure Map from Petite Caverne
Loot the skeleton right behind the previous chest.
Solution: Tulum (40, 372 – at the southernmost tip of Tulum, at the beach behind a shipwreck
Cumberland Bay
#54 – Art Piece: Pedestal Bowl
Inside a small tent of an enemy camp.
#55 – Letter “Another Fryghtful Reverie”
On the beach of a very small island, opposite the main island.
#56 – Treasure Map from Cumberland Bay
Loot the skeleton on the beach on the south side of the island.
Solution: Pinos Isle (304, 455 – in the north-west corner of the temple with the viewpoint, in the grass
Cruz Region
San Juan
#57 – Weathered Map Piece
The chest is on the left side of the cave, behind the data file. To open the chest, you need to loot the key from the bigger enemy that is walking around. This will also unlock Among Thieves if you do not have it already.
Grand Cayman
#58 – Art Piece: Yoke-Form Vessel
Next to the viewpoint, you will see and hear a drunken man. The only way to reach him is to get to the tavern nearby and get drunk. To get drunk, you need to buy five drinks. This costs 125 Reales in total. After that, you will wake up in the haystack behind that drunken guy. This will also unlock Hungover. Now you can open the chest.
Devil’s Eye Caverns Wreck – accessible after Sequence 06 – Mission 01: Diving for Medicines
#59 – Ship Upgrade Plan: Swivel Guns Ultimate Plan
From one of the underwater chests.
Castillo de Jagua Region
Cayman Sound
#60 – Art Piece: Tripod Vessel with Date Glyph
On the western part of the island, underwater, near a shipwreck.
#61 – Treasure Map from Cayman Sound
On the northwestern part of the island, on the beach, near a rock.
Solution: Petite Caverne (863, 235 – go to where the Hutia hunting spot (rat icon is in the southern edge of the cave. It’s behind the rocks with a waterfall.
#62 – Letter “The Assassyn”
Northern part of the island.
Pinos Isle
#63 – Treasure Map from Pinos Isle
In front of the ruins on a skeleton.
Solution: Cayman Sound (304, 310 – in the north-east shore of Cayman Sound, between the palm trees
#64 – Manuscript “Mayan Dresden Codex”
Climb up the wall behind the treasure map to find this secret chest.
Arroyos
No Secrets in this area.
The Black Trench Wreck – accessible after Sequence 06 – Mission 01: Diving for Medicines
#65 – Rare Cutlass – Espada Ancha
From one of the underwater chests.
Conttoyor Region
Sacrifice Island
#66 – Trinket: Anchor Medaillon
Southwest part of the map, inside the ruins.
#67 – Sword: Captain Drake’s Swords
Western part of the map. Before you climb up the wall to the northern viewpoint.
#68 – Outfit: Captain Drake
On the east side of the map, in front of the island under the water.
Tulum – northern part of Tulum is explorable after Sequence 04 – Mission 03: The Sage’s Buried Secret
#69 – Art Piece: Cabinet
To the north of the northern viewpoint. Go down the wooden walkway.
Chinchorro Region
Santanillas
#70 – Letter (“The Templar Arrives”)
Found on the beach in the Northwest corner of the island.
#71 – Treasure Map from Santanillas (San Juan)
Located on the cliffs above in the rock valley on a skeleton.
Solution: San Juan (455, 462 – swim into the cave through the underwater tunnel, as soon as you exit the water there will be a cave section with a single enemy. The treasure is there on the right, just before climbing up the wooden scaffold.
#72 – Art Piece – Beaver Pelt
Located on the West side of the island in a little outcrop.
Corozal
#73 – Treasure Map from Corozal (Ambergris Key)
This treasure map is on a skeleton on its own small island in the Northeast side of the island.
Solution: Ambergris Key (30, 157 – to enter Ambergris Key, you need to dive down at the entrance and follow the red jellyfish through the underwater tunnel. Once you reach the inside, check the left corner before climbing up.
#74 – Letter (“Finding Steady Work”)
On the back in a bottle on the South side of the West portion of the island.
#75 – Art Piece – Bust of a water deity
Found underwater just off the West of the island.
Ambergris Key
#76 – Letter (“On Being a Sage”)
Found on the floor of the ruins upon entering the cave from underwater.
#77 – Weathered Map Piece
Inside the ruins in the cave. Need the Ambergris Key Smuggler’s Chest Key obtained by looting enemies here.
#78 – Treasure Map from Ambergris Key (Misteriosa)
From the Northwest corridor in the ruins you will see some barrels and rubble you can climb while facing Southeast. Climb up and the map will be lootable off a skeleton in the hallway.
Solution: Misteriosa (271, 178 – Fast travel to the viewpoint but turn around instead of jumping down, you’ll see a water fountain behind the mayan temple (on the top level. The buried treasure is to the left of the fountain in the grass, behind tall white flowers.
La Concepción Wreck – accessible after Sequence 06 – Mission 01: Diving for Medicines
#79 – Ship Upgrade Plan: Ram Ultimate Plan
From one of the underwater chests.
Serranilla Region
Misteriosa
#80 – Manuscript – “Atalanta Fugiens”
Located in the highest room in the ruins next to the Viewpoint in this area.
#81 – Treasure Map from Misteriosa (Kingston)
Located on a skeleton lying on the side of the ruins overlooking the island just below the first Mayan Stelae.
Solution: Kingston (631, 152 – on a small beach in the south-east of Kingston, between two pieces of a broken boat in the sand
#82 – Letter (“My Apprenticeshop”)
Located on the portion of island sticking out to the East.
New Bone
#83 – Art Piece – Vulture Vessel
Head into the jungle near the warehouse the opposite way of the Mayan Stelae. Follow the path to a campsite. Take out the enemies there and look to the East and you will see a path up to the ruins above where this chest is.
Isla Providencia – only reachable during/after Sequence 08 – Mission 03: Marooned
#84 – Letter “Earlie Opinions of My Condition”
On the rocks at the beach below the southern viewpoint.
#85 – Manuscript “Sacred Theory of the Earth”
From the western viewpoint follow the river, at the bottom of the river take the right path. Then keep to the right to find this to the side of an area with water.
#86 – Treasure Map from Isla Providencia
Fast travel to the Jackdaw by the beach in the west of Isla Providencia. On the side of the beach go up the muddy slope to find this at the end. If you fully zoom in on the map you can see the brown muddy path between the trees (to the north of the treasure map icon on the map.
Solution: Long Bay (503, 230 – Long Bay is only accessible after advancing the story to Sequence 10 – Mission 03: The Observatory, you can’t get the treasure before then. Next to the viewpoint are 3 huts at the beach. Check the sand slightly south of the 3 huts.
Charlotte Region
Anotto Bay
#87 – Weathered Map Piece
Head into the underwater tunnels until you emerge in a mineshaft filled with enemies. You will need to defeat all of the enemies here to receive the Anotto Bay Smuggler’s Chest Key so you can open the chest.
Long Bay – only reachable during/after Sequence 10 – Mission 03: The Observatory
#88 – Art Collection: Art Piece – Bracelet
On the top floor of the cave that leads from the northern viewpoint to the southern viewpoint. When coming from the northern viewpoint stay on the top floor and turn right to find it in a side section.
#89 – Letter – “A Secret Incomprehensible”
At the bottom of the cave in a side room.
The Blue Hole – accessible after Sequence 06 – Mission 01: Diving for Medicines
#90 – Ship Upgrade Plan: Broadside Cannons Number Ultimate Plan
From one of the underwater chests.
Navassa Region
Kingston
#91 – “Magellan’s Ship” (Manuscript)
Located in the West Wing on the second floor of the Plantation House on the West side of Kingston.
#92 – “World Map” 1570 (Manuscript)
In the top Northwest corner of Kingston there is a small campsite with British enemies. This chest is in this camp.
#93 – Art Piece – Triptych
Just North of the church in a gazebo in a courtyard surrounded by enemies.
#94 – “De Gama Diary Extract” (Manuscript)
Located on the Southeast side of the island in a small court behind a barn.
Port Royal
#95 – “Voynich Manuscript” – Folio 33v (Manuscript)
Located in the Northern section of the Restricted area in the South.
#96 – Treasure Map from Port Royal (Principe)
Located on the East of the island in a cemetery on a skeleton.
#97 – “The Fetus In The Womb” (Manuscript)
Located in the Northeast portion of the island in a small encampment with privateers.
Île à Vache
#98 – “Voynich Manuscript” – Folio 34r (Manuscript)
Under covering at a campsite in the Northeast corner.
#99 – Treasure Map from Île à Vache (Jiguey)
On a skeleton along the beach’s shore in the Northeast.
Solution: Jiguey (534, 510 – inside of Jiguey cave, in the section with pirate enemies swim forward to the beach where a brute (big enemy is, the treasure is on the right side of the beach in the sand between the palm trees.
#100 – Letter – “Taking My Leave”
Located in a bottle on the shore on the Western side of the island.
Mystery Island
#101 – Stede Bonnet’s Attire (Outfit)
Located on the upper cliffs in the encampment.
#102 – The Revenge’s Sails (Ship Cosmetic)
Located in the lake in the center of the island closest to the shore where you dock your boat.
#103 – Revenge Figurehead (Ship Cosmetic)
Located on the cliffs in the Eastern side of the island.
Kabah Ruins – accessible after Sequence 06 – Mission 01: Diving for Medicines
#104 – Ship Upgrade Plan: Round Shot Strength Ultimate Plan
From one of the underwater chests.
Princípe Region
Princípe – only reachable during/after Sequence 09 – Mission 02: Trust is Earned
#105 – Officer’s Outfit (Rare Outfit)
On a small awning on the docks. You can get back to Principe after Sequence 09 by clicking the white “P” icon on the right of the main map (939, 415).
That’s all of the Secrets in AC IV Black Flag (2026 Remake). For all other collectible types refer to the Assassin’s Creed IV: Black Flag Resynced Collectible Guide.
Leave a Reply