Herculaneum was a small township on the slopes of Mt. Vesuvius, not far from the Greek colony of Neapolis. In 24 August 79 AD the sudden and unexpected awakening of the Vesuvius overwhelmed the town with clouds of scorching toxic gas, alternating with torrents of volcanic mud. The town's remains include the cardos and the houses along them, the main baths, the sacred precinct, the palaestra and more. In 1997 Herculaneum was declared a World Heritage site by UNESCO, together with Pompeii and Villa Oplontis.