Summer doesn't last long in Prague, and when it arrives, many city dwellers are only too happy to cool off in one of the city's many pools. In addition to the hotel pools listed in chapter 5, there's the Dzbán Reservoir, in the Sárka nature reserve, Praha 6. Dzbán is fronted by a grassy "beach" that can -- and often does -- accommodate hundreds of bathers. There's a special section for nude swimming and sunbathing. To reach Sárka, take tram no. 26 from the Dejvická metro station. If you prefer a swimming pool or the weather doesn't cooperate, visit one of Prague's best aqua centers. The Letnany Lagoon, Tupolevova 665, Praha 9-Letnany (tel. 283-921-799; www.letnanylagoon.cz) has got a full-length pool as well as Jacuzzi and toboggan, which is a good fun for the whole family. You can also get a little refreshment and a drink while around the pool. The Lagoon is open Monday, Wednesday, and Friday 6 to 9am and noon to 10pm; Tuesday 7 to 9am and 4 to 10pm; Thursday 7 to 9am and noon to 10pm; Saturday and Sunday 9am to 10pm. Admission is 140Kc ($5.85) adult, 70Kc ($2.90) children for 2 hours. To get there take bus no. 210 from metro line C Holesovice to the Tupolevova stop at Letnany.