Venice, Italy
Venice is one of the most interesting cities because it's so different. Take a walk around and get lost, you probably will if you start to really explore. Venice, unfortunately, has become quite a tourist place and all of the main areas are geared towards their business. The backstreets and alleys is where you'll find more authentic sights.
The streets are extremely narrow and you'll find yourself surrounded by buildings making it difficult to get your bearings. But enjoy it, there's always a shop to peep into, and you'll find a lot to see and take photos of.