Danube Island (Donauinsel)

A long stretch of island, and a long stretch of fun
Word to the wise: Both ends of the island are nudist areas, which is good to know, in case you forgot to pack your bathing suit.

Donauinsel extends 21.1 kilometers in length, dividing the Danube River in two. Come summer, this island makes a perfect setting for a leisurely bike ride, or if you prefer, inline skating. There isn’t a ton of sandy coastline to launch into the water from, but there are a few spots here and there. Some people complain that the nature found on the island has a bit of an artificial feel (it is an artificial island, after all), but it’s not bad for an urban environment.
The long bike path is littered with bars and cafés, where you can relax between rides and strolls. In the summer, you can take advantage of the outdoor seating areas in the pubs, and listen to some of the concerts and live music held on the island when the days are sunny and warm.