This favourite hangout for the sun loving Czechs was the subject of one of Smetana's best-loved compositions which everyone will know as "The Vltava". It is a relatively pollution- free river which flows from the Southern border of the Czech Republic through Prague to the Northern border. The river runs through many of the countries small historical towns and is broken at various points by dams. Canoeing and sailing not to mention picnics and bathing are very popular during the summer and fishermen in their boats can be seen almost all times of the year in reasonable temperatures. For the visitor to Prague the river might be a way to view many of the best parts of a town at leisure. Boat trips night and day regularly wind their way up to as far as Vyshehrad castle and back offering music, drinks and meals along the way. During the summer a boat on weekends will take you for a day trip as far as the Slapy Dam 20km south of Prague.