An underground river, the Amenano, flows through much of Catania. You can glimpse it at the Fontana dell'Amenano, but the best place to experience the river is at the bar-restaurant of the Agorà Youth Hostel. Here you can sit at an underground table as swirls of water rush by. If you're not there when the bar is open, someone at the reception desk can let you in. Apart from the underground river, the bar area aboveground is a lively, fun area to hang out on a Monday evening when many other places are closed.