This guided tour gets you past what's free to see in Prague's Old Town – the square, Týn Church, and the Astronomical Clock's exterior – and into what isn't: the Old Town Hall's interior and a 12th-century underground complex most visitors walk straight over without knowing it's there. The clock itself, mounted on the Old Town Hall since 1410, is the oldest working astronomical clock anywhere.
The clock itself
Every hour from 8am to 11pm, the clock's "Walk of the Apostles" draws a crowd – 12 apostle figures appear in two small windows as the hour strikes, alongside a skeleton figure representing Death, tolling the bell. The clock survived centuries largely intact until the 1945 Prague Uprising, when Nazi forces shelled the square and badly damaged both the mechanism and its wooden figures; full repairs weren't finished until 1948.
What's actually inside
The Old Town Hall interior and the underground complex beneath it are the parts you can't just wander into on your own – stone-vaulted rooms from the city's medieval foundations, sitting well below current street level. The walking portion of the tour also covers the Jewish Quarter, rounding out the historic core beyond just the main square itself.
Booking
The guided tour runs two to three hours and is a popular, frequently sold-out option, so book a day or two ahead. It's best treated as an add-on to time spent freely walking the square yourself, not a replacement for it.
Good to know
Frequently asked questions
It dates to 1410, making it the third-oldest astronomical clock in the world and the oldest one still working. The calendar dial and the moving apostle figures were added later, over the following centuries.
Image: Jorge Royan via Wikimedia Commons (CC BY-SA 3.0)