This locked chest is the only Criptograma Chest on Isla Santuario, hidden on the starting island. Find its two Criptograma Charts and it opens to give you a piece of unique gear.
Look north of Armonía for a house with the chest on its porch, beside a bag of trash. Listen for the wind chimes as you get close.
The chest stays locked until you have both of its charts. Look for Guerrilla Sigils, the guerrilla markings painted near the chest, and follow them to each Criptograma Chart. Once you have both charts, go back to the chest and open it.
Inside is the Hazmat Gloves MK II. The two charts you used are also added to your Criptograma Charts collection, so every chest you open moves both lists forward.
Image: UbisoftCriptograma Charts
Criptograma Charts are the coded symbol sheets that open Criptograma Chests. Every chest needs two of its own, so you hunt down 30 charts in all to empty the 15 chests on Yara.
Criptograma Box 1 - Aguas Lindas
This locked chest is the first of Madrugada's four Criptograma Chests, hidden in the Aguas Lindas area. Find its two Criptograma Charts and it opens to give you a piece of unique gear.
Image: UbisoftCriptograma Box 1 - Barrial
This locked chest is the first of Valle De Oro's four Criptograma Chests, hidden in the Barrial area. Find its two Criptograma Charts and it opens to give you a piece of unique gear.
Image: UbisoftCriptograma Box 1 - Esperanza
This locked chest is the first of Esperanza's two Criptograma Chests, hidden in the capital. Find its two Criptograma Charts and it opens to give you a piece of unique gear.