One dorm had a large common shower area. Toilet stall doors were removed and used to block off the doorway into the shower area to a height of 3-4 feet. The shower drains were plugged up, and the showers turned on, creating a large indoor pool.
The next year another dorm had a large pile of sand around the side of it. Shower curtains from several floors were taken down and used to line the lounge floor on one floor. The sand was transported in using a large rolling metal mop bucket, and dumped on the curtains to a depth of 2-3 inches, creating an indoor sandy beach for a beach party.