Hostivař Reservoir, reservoir in Prague

Hostivař Reservoir is a freshwater lake in the Hostivař Forest Park on the eastern edge of Prague, lined with a long sandy beach and a wide pier that extends into the water. It is the city's largest outdoor swimming area, with grassy banks, changing facilities, and space for sports such as volleyball and fishing.

The lake was created in the mid-20th century by damming the Botič river, primarily to protect surrounding areas from flooding. Over time it became one of the most visited outdoor spots in Prague, drawing people from across the city each summer.

The reservoir has a dedicated nudist section that has been in use for decades and is one of the oldest of its kind in the country. This part of the shore sits apart from the main beach and draws regulars who treat it as a normal part of summer life in Prague.

The reservoir lies on the Botič stream at the southeastern edge of Prague, with its water surface reaching into Prague 11, Prague 15 and Petrovice. The main beach is reached from Hostivař, the Košík housing estate and Slunečný vršek, while the smaller rear beach is entered mainly from Jižní Město and Petrovice. A wooden pier stands in the western part, and a 70 m wooden rest pier was built on the right bank during the 2010–2012 revitalisation.

The 70-metre wooden rest pier on the right bank was built during the 2010–2012 desilting, when 198,000 m³ of sediment were removed from the bed. Two pebble islets were also created in the upper part of the reservoir as nesting sites for birds.