Off to your right is a building with a hidden past. It was a 17th century pleasure house where noble men go to live out their fantasies. The house had 6 escape doors in case of a raid. Not all noble men allowed entry. The madame carefully screened her clients through a hole (above the door). If the door opens, enjoy. If the door stays locked, well, you must hit the road or in this case, get back on your gondola.