We just recently returned home from a trip to Pop Century staying in building 5 this trip and there were carts of towels left near the elevators of our building daily (and replenished all day long) for the pools. We have been to Pop numerous times and more often than not, there has been a similar cart of towels left in the same area of our building. They left them on the 1st floor across from the elevators. We have seen them left out years ago at AS Movies as well. So while it may not always happen, you might get lucky and have a cart of towels in your building. If not, just ask for extras from Mousekeeping.