A vast ribbon of greenery looping along the Danube from the fringes of Vienna to the Slovakian border, the 9300-hectare Donau-Auen National Park is one of the last remaining major wetlands in Europe. Established in 1996, the park comprises around 65% forest, 20% lakes and waterways and 15% meadows, which nurture some 700 species of fern and flowering plants.

The park's quieter reaches attract abundant birdlife and wildlife, such as red deer, beavers, fire-bellied toads, eagles, kites and a high density of kingfishers. The wien-lobAU National Park House, located at the northern entrance to the park, offers a series of themed guided tours, ranging from winter walks to birdwatching rambles, most of which cost around €10/5 for adults/children. Boat tours into the national park leave from Salztorbrücke and last 4½ hours; booking is necessary. See the website for further details.