Danube Island

The Donauinsel is how Vienna does summer. It is a long, narrow artificial island, about 21 kilometres from end to end, created between 1972 and 1988 when the city dug a parallel flood channel, the New Danube, and piled the spoil into a strip of land between the two arms of the river. What began as an engineering project to protect the city from floods became one of the largest urban recreation areas in Europe, planted with more than a million trees and shrubs and laid out with meadows, woodland and miles of shoreline. The calm water of the New Danube is clean enough to swim in, and the island and its banks offer dozens of kilometres of free sand, gravel and grass beaches, from family-friendly bays with gentle shallows to quieter stretches in the north and south, including designated naturist areas. Around 135 kilometres of paths run over the island and connect to the long-distance Danube Cycle Path, making it superb for cycling, inline skating and running; a flat loop along the New Danube is a favourite with Viennese runners. In the middle, near the U1 station, the island turns lively: Copa Beach on the city bank and the Pier 22 area on the island side have waterfront bars, restaurants and loungers, linked by a footbridge, and the large festival meadow hosts concerts, sports events and festivals all summer, including one of Europe's biggest free open-air music festivals, the Donauinselfest, usually held in June. Further out, the island becomes almost wild, with long empty shorelines, reeds and herons. Entry is free, it is reached in minutes by U-Bahn from the centre, and on a hot day it is where you will find half the city.

How to visit: take the U1 to Donauinsel station, which drops you right in the middle of the island near Copa Beach and the bars, or the U6 to Neue Donau or Handelskai for the western side. Bike-sharing stations and rental shops make it easy to cover distance, and a bike is the best way to experience the island's length. Bring your own towel and water if you are heading for the quieter beaches, where facilities are limited; the central area has kiosks, toilets and restaurants. Swimming is unsupervised in most places, so families should choose the designated family bays with gentle entry.

When to go: June to early September is the swimming season, with long light evenings when the waterfront bars fill up for sunset. Spring and autumn are perfect for cycling and walking, with far fewer people. In winter the island is quiet and windswept but still good for a bracing walk or run. If you visit during the Donauinselfest weekend in June, expect huge crowds, free concerts and a very festive atmosphere; outside that, even on the hottest days, a short cycle away from the centre finds you a peaceful spot.

Who it suits: families looking for a free beach day in the city; couples after a sunset drink by the water; active travellers who want to run or cycle; and anyone visiting in a heatwave. It pairs naturally with the Danube Tower and the Donaupark across the water, the Old Danube lake with its lidos and boat rentals, and the Prater, two stops back towards the centre on the U1. It is also a smart answer to a crowded sightseeing day: twenty minutes from the Hofburg, you can be cycling along open water with the Vienna Woods on the horizon and barely another tourist in sight.