In Shadow of the Tomb Raider there’s a hidden crypt in Mission of San Juan area. You may have unlocked it on the map already by picking up one of the Explorer Backpacks in the region and may now wonder how to get to the crypt which is seemingly unreachable.
The Crypt in Mission of San Juan is bound to the Side Quest Explore the Local Mysteries. Do that quest and it will lead you to the Crypt. There is no way to reach it outside the quest.
Talk to the quest giver in San Juan, as shown below:
From there simply follow the waypoints of the mission or refer to our Shadow of the Tomb Raider Explore the Local Mysteries Side Mission Walkthrough.
You can access it without the quest but you can’t exit the crypt so it’s eventually pointless. There is a slippery slope at the end of the road which leads out of the village. You can spam jump on this slope and eventually Lara will attach to a tree which allows you to jump on top of the slope and descent the tower from a higher point than it’s intended.
You can not climb back up and the actual entrance to the crypt will still be blocked if you don’t follow quest waypoints.