The Clementinum Baroque Library

The Clementinum is a vast former Jesuit college filling a block between the Old Town streets and the river, now the National Library. Its Baroque Library Hall, finished in the early 1720s, survives with the original bookcases, a frescoed ceiling and a line of geographical and astronomical globes down the middle; you look at it from the doorway, behind a rope, because floor and bindings are fragile. The tour continues up the Astronomical Tower, where temperature has been recorded since the eighteenth century, past the meridian hall once used to fix local noon, to a balcony over the Old Town roofs. The mirrored Baroque chapel below is used for concerts.

What you actually see

• The library hall - frescoed ceiling, original shelving and a row of antique globes.
• The Astronomical Tower - a narrow stair climb to a balcony above the Old Town roofs.
• The meridian hall - the room where a sunbeam through a slot marked midday.
• The mirrored chapel - stucco and mirror panels, still used for evening concerts.

When to go

Tours run through the day in Czech and English and fill up in summer, so book a slot rather than turning up. Late afternoon light is best from the tower balcony. Winter is quieter and the complex is warm, but the tower can shut in ice or high wind. Concerts in the chapel are ticketed separately.

Honest expectations

You see the library from a rope at the door and cannot walk in, which disappoints anyone expecting to wander among the books. Photography in the hall is restricted. The tour is short for the price, groups can be large enough that you hear little of the guide, and the tower stairs are steep and narrow. Ticket sellers outside the complex are persistent.

Nearby

Charles Bridge and the Old Town lanes are a few minutes away.