An underwater volcano with a base larger than Washington, DC has been discovered off the coast of Sicily. Named for the Greek philosopher Empedocles, the mountain incorporates peaks previously believed to be separate volcanoes, and is 30 km (18.6 miles) long at its base, and at least 400 meters (1,300 feet) high. It was identified during research into the submerged volcanic island of Ferdinandea, which researchers now say is part of Empedocles.