South of Prague, the Vltava leaves the city through a deep, wooded valley, and the suburbs give way to villages, orchards and cliffs. It is a place of transition: the city's traffic behind you, the Bohemian countryside ahead.
The Vltava is the river of Smetana's famous symphonic poem, and its course south of Prague is a chain of dams and reservoirs, beginning at Vrané with a small dam and power station, then rising toward the larger lakes at Slapy and Orlík. The valley is lined with weekend cottages, a Czech institution: under communism many families built small chatas in the countryside, and the tradition of leaving the city on Friday evening is still strong. Zbraslav, on the river nearby, has a former Cistercian monastery turned chateau.
The rides from here head west to Karlštejn and the Berounka. Karlštejn Castle, built by Emperor Charles IV in the fourteenth century to protect the crown jewels and his collection of holy relics, rises from a wooded hill above a narrow valley, with towers stepping up to the Great Tower and its chapel decorated with gold and precious stones. The surrounding Bohemian Karst is a landscape of limestone cliffs, caves and quarries, including the flooded quarry known as Velká Amerika, sometimes called the Czech Grand Canyon, and the Koněprusy Caves. The Berounka valley itself winds through forest, with roads following the river in long curves.
The roads around here are mostly narrow, with variable surfaces, cobbled sections in some villages, and tight bends through the woods. Weekends bring cyclists and day-trippers, and the road to Karlštejn can be crowded. Remember the Czech rules: dipped headlights are required at all times, and the legal alcohol limit for drivers is zero. Prague itself has trams, cobbles and congestion, so leave early to avoid the city's traffic.
For fuel and supplies, Modřany and Zbraslav are close, as are the larger towns along the main roads. Village pubs serve hearty Czech food, such as goulash, roast pork with dumplings and sauerkraut, and of course excellent beer, which is for the evening, not the ride. Bring a jacket, as the river valleys can be cool and damp in the morning, even in summer.