There are a total of 15 Criptograma Chests and 30 Criptograma Charts in Far Cry 6. Criptograma Chests get marked on the map as you get near it. To open a Criptograma Chest you will need to find 2 Criptograma Charts nearby, which act as keys to open the chest. On opening the chest you will find a Piece of Armor.
You will find blue markings pointing towards the charts. There is also a wind chime near the chest and charts. You can follow the noise of the wind chime to locate them. This article shows the location of Criptograma Chest & Criptograma Charts in the La Joya region in El Este.
La Joya Criptograma Chest and Criptograma Charts #21 & #18
The Criptograma Chest is at the roof of The People’s Pride Clinic in the La Joya region in El Este.
Criptograma Chart #21: The chart is on the rooftop of the building near the beach as shown below. You can climb to the rooftop using the scaffolding on the north side of the building.
Criptograma Chart #18: After you have got the previous chart, look south and chart #18 is at the top of the building shown below. Jump down and go to the center of the apartment complex. Use the grapple to reach the roof of the building next to the building with chart #18. From there, use the zipline to reach the roof with Chart #18.