St Vitus Cathedral within the grounds of Hradcany (the castle district) in Prague. This is an absolutely fascinating building with beautiful stained glass windows. On the exterior it is Gothic in style and there are many carvings and statues all around, many of very peculiar gargoyles.
This is the view from the top of the spire. It is well worth the climb of 300 steps, which was very arduous as it was so crowded and hot. But the view!! Amazing.