Prague Castle dominates the sky-line of the Czech capital and is one of the most potent symbols of this country's culture and history. A new exhibition, at the Castle, features haunting and intriguing photographs of the former seat of Czech kings - from the days when the art of photography was very much in its infancy.
It's a sunny but breezy October afternoon here at Prague Castle, where hundreds, possibly thousands, of foreign tourists have gathered to watch the changing of the guard. But the Castle looked very different when the first photographs were taken here - 149 years ago.
"This is the oldest known photograph of Prague Castle, and it dates from 1856. It was taken by a Viennese photographer called Andreas Groll, on his first visit to Prague."
says Pavel Scheufler is the man behind the exhibition.
Many of the photos are taken from below and from the banks of the River Vltava; they bring to mind the dark, forbidding Castle of Franz Kafka.
"Kafka actually lived for a while up here at the Castle, in Golden Lane. But many of these photos here are actually from before his time. He was born in the 1880s so he didn't know the Castle in its really ancient form; it was changing in his day. For instance, the towers of St Vitus's Cathedral date from 1892."
"Many people will be fascinated to learn that the frame of the roof of St Vitus's Cathedral is actually made of metal. We have some great pictures here of the completion of the roof. This one shows workers who have clearly been posed by the photographer - it looks almost modern and avant-garde."
But there are few people in these photographs taken between 1856 and 1900. Pavel Scheufler explains why.
"19th century photography is different from 20th century photography. Many of these pictures were taken using the complicated wet collodion process, in which exposure took a few seconds. So there are very few people, or even clouds. There are exceptions - in this photo, for instance, there are posed figures who are really clear, but this figure is transparent because the person walked in front of the camera during exposure."
The exhibition runs until mid-January.