Okay, so an insane asylum might not sound like the most enjoyable place to spend an afternoon while on holiday in Venice, but there’s no denying it can be a hugely fascinating experience. San Servolo Island earned the unflattering nickname the ‘Island of the Mad’ by serving as the official mental asylum for Venice from 1725 until 1978. It has been open as a museum since 2006. Divided into nine sections (one of which is cheerily titled ‘the Sick’) and containing a photo album of patients, this is one of Venice's most macabre yet captivating sights. Vaporetto 20 makes the 10-minute journey here from the San Zaccaria pier near San Marco every hour or so.