The medieval Astrological Clock might be the most frequently visited and photographed object in Prague. It was installed in 1410 against the side of the Old Town Hall, the third astronomical clock in the world and the oldest still in operation.
It is lovely to see the details.
And from lunch on the second floor of Cafe Mozart, across the way.
Old Town Square at this time of the year hosts a fairly large Christmas Market, with more "permanent" looking booths than in many other cities. There are fewer gift shops and more food and beverage shops.
I prefer the markets in Dresden and Berlin.
One feature of the Old Town Square that I loved was the Jan Hus Monument in the approximate center of the square. Hus was the dean of Charles University in Prague. A hundred years before Martin Luther, Hus criticized the Catholic Church for selling indulgences. The Pope's followers invited Hus to renounce his views. He declined and was burned at the stake in 1415, setting off waves of wars. This memorial by Ladislav Saloun was installed on the 500th anniversary of his death, in 1915.