Well of Tears

 is a challenge tomb in Tomb Raider.

Location
Well of Tears is in Shanty Town under the house with the sacrificial altar inside. The entrance to the tomb is right next to the lockbox, openable with a rope arrow. There are some steep ledges before reaching the tomb itself.

Walkthrough
There are four gas canisters laying around the room, but you only need three of them to pull the hanging contraption down. One the contraption is on the floor, jump inside it and toss the canisters out again, while standing inside it to weigh it down. Once empty, race to the highest ledge and jump on the contraption while it is rising, and then jump to the left to reach the ledge leading to the treasure. Once the treasure is looted, use the rope to slide back down safely.