Prague's best-known sights sit on one line: a medieval clock in the Old Town, a stone bridge over the Vltava, a wall of messages in the Lesser Quarter, and the castle on the hill above. Walk them in this order and the city tells its story in sequence, from merchants and astronomers to kings and protest songs.
It is a walk of four stops and one long climb at the end, so save your energy for the castle.
1. The Astronomical Clock
Start on the southern wall of the Old Town Hall, where the Astronomical Clock has kept time since 1410. It was made by the clockmaker Mikuláš of Kadaň with Jan Šindel, a professor of mathematics and astronomy at Charles University.
On the hour, Death, a skeleton, rings his bell while the figures beside him shake their heads, and the Twelve Apostles pass by in the two windows above. The show is short, so arrive a few minutes early. Much of what you see was rebuilt after the hall burned in the Prague uprising of May 1945.
2. Charles Bridge
Head west through the Old Town lanes to the river. Charles Bridge was begun in 1357 under King Charles IV, and today it belongs to people on foot alone.
Thirty statues, most of them Baroque, line its balustrade. Since 1965 the originals have been replaced one by one with copies, and the originals moved to the Lapidarium of the National Museum. Cross slowly: the view of the castle grows with every step.
3. The Lennon Wall
Just off the bridge, in a quiet square across from the French Embassy, is the Lennon Wall. After John Lennon's murder in 1980, someone painted his face and some lyrics here, and the wall became a place for messages of love and protest under the communist regime.
It belongs to the Sovereign Military Order of Malta. Spray paint is banned now, but you may add a message in pencil, marker or chalk in the marked zones.
4. Prague Castle
Now climb. Prague Castle was founded in the 9th century and has been the seat of Bohemian kings, Holy Roman emperors and presidents. Guinness lists it as the largest ancient castle in the world, at almost 70,000 square metres.
Inside its walls stand St Vitus Cathedral and a hidden room that keeps the Bohemian Crown Jewels. Arrive around noon to see the ceremonial changing of the guard in the first courtyard.
In four stops you have crossed from the city of traders to the city of rulers, with a bridge and a wall of songs in between. From the castle, look back over the river: the whole walk lies below you.