L'Aquila lies at the foot of the Gran Sasso. According to legend, the city was founded in the 13C when inhabitants from 99 castles decided to form a single town, in which each castle had a church, square and fountain. By the 15C, L'Aquila had become the second most important city in the kingdom of Naples, thanks to the cultivation of saffron or "red gold", which was grown on the Navelli plateau and sold throughout Europe. Many of the city's monuments date from this time. This extremely rich artistic and historical city was seriously damaged during an earthquake of 6.3 magnitude on 6 April 2009 with tragic consequences.