One day in Prague is enough to see the icons, but not the whole city, so this route deliberately skips the smaller museums and neighborhood detours in favor of the sights that define Prague. It moves from the castle hill down through the Lesser Town, across the river, and into the Old Town before closing with a hilltop view.
Arrive early at Prague Castle (Pražský Hrad) before the tour groups, and use your time inside the complex to see St. Vitus Cathedral and St. George's Basilica. Walk down through Malá Strana (Lesser Town), pausing at St. Nicholas Church (Malá Strana), then cross the river on the famous Charles Bridge (Karlův Most), passing under the Old Town Bridge Tower as you enter the Old Town. In the early afternoon, reach Old Town Square (Staroměstské Náměstí), timing your arrival for the top of the hour to catch the show at the Astronomical Clock (Prague Orloj), and step inside the Church of Our Lady Before Týn nearby. Spend the rest of the afternoon in Josefov (Jewish Quarter), where the Old-New Synagogue (Staronová Synagoga) is the oldest active synagogue in Europe. As evening approaches, head to Petřín Hill & Tower for sunset views over the whole city before dinner back in the Old Town.