To reach this location, you need to use Gaia's Underpass - the only tomb in Asylum. This is one of the more important locations in Assassin's Creed: Odyssey Fate of Atlantis, as you'll visit it while completing story missions.
Follow the corridors until you encounter a path that is blocked.
Move the front stillages to make room on the right side of the room. This way, you'll get through the blocked path safely.
Break the vase found on the left side of the wall and proceed to the next part of the cave.
There is a crumbled wall behind the statue found on the left side of room. Destroy it and follow the new path.
Once again, you'll encounter movable stillages. Place them in such a way as to unlock the path. Behind them, there is another weakened wall - you can destroy it using your torch.
When you get through the traps, you'll find yourself near Dead Heroes Haven. All you have to do is to activate the table, and you'll clear the area.