Here is another installment of exTRAPaganza, our Thursday over-the-top trap series.
At the center of the tower is a large circular room with about a dozen doors. This room can only be reached via a one-way teleport gate.
At some point, one of the doors opens and water begins to pour in. The door can be shut to stop the water. However, when it is shut, another random door, preferably one that hasn’t been secured or isn’t manned, opens.
A single open door will completely fill the room with water in 10 minutes. Each door opens up to a vertical shaft with a ladder. These are completely full and require a hard Strength (Athletics) check to climb, due to the water pressure. They are each 100 feet high. If the door is shut, after 2d8 rounds, the water will quiesce and it can be climbed via a normal swimming check.