Walking the length of the island takes about 20 minutes, but most visitors spend time at the Hajós Alfréd and the Palatinus outdoor pools. The Palatinus water park is a popular place in the summer, especially on the weekends. The 11 outdoor pools, including two for children, are in a beautiful setting. If it is too cold to go for a swim, an island tour introduces relics hailing back to the island's religious origins, including a 12th century convent and ruins of a Franciscan and a Dominican church. During summer months, bicycles, inline skates and 'bringóhintó', a four-wheeled bike for four, are available for rent. Since vehicles are prohibited, the island is a fantastic escape from the bustle of the big city and a great place to work out, swim a few laps, or go for a run.
Other attractions on the island include the Centennial Memorial which commemorates the 100th anniversary of Budapest, a Japanese Garden, a tiny zoo, a music fountain, and an octagonal water tower, built in Art Nouveau style in 1911. The outdoor theater hosts operas, concerts and plays during summer.
The thermal water on Margaret Island is famous for its healing effects. The natural, thermal water running beneath the island was first brought to the surface in 1886. In addition to its healing power, a day at the Danubius Health Spa is also a great way to relax and unwind. http://visitbudapest.travel/guide/budapest-attractions/margaret-island/