Famed for various historical and geopolitical events, it has been the location for documentaries and films, is a popular tourist destination and a jewel of the province of Rimini. Its extraordinary geological configuration, on a rocky mass with sheer sides, has determined its dual military and religious importance since prehistorical times, testified by precious architectural and artistic artefacts. The highlight of San Leo is the stunningly located castle, on a large craggy rock above the village (or rather a precipitous cliff, on one side) - and very well worth the short steep climb from the village. It even impressed Dante, who based his descriptions of purgatory on the site. More info here.