Note: This crypt requires the shotgun, so return here once you have finished Chapter 5 - Cenote.
Start out at the Hunting Grounds Base Camp and head forward past the mural, then turn off to the right along a shallow river with a plateau in the middle.
Head to the back of this area to find a metal barrier on the left-hand side. Destroy the barrier with your shotgun to reveal a single, tiny room with the sarcophagus.
Loot it to receive the outfit piece CONDOR COWL OF URQU.