Charles Bridge itself creates a beautiful foreground for photographs of the surrounding Prague. In the west direction, mainly the Lesser Town Tower Bridge and the Prague Castle dominate the scenery, while the statues and old lanterns add depth to the scene.
Photo tips: Charles Bridge is very popular, so expect a lot of people here. It's much better in the mornings, but evenings are crowded here. However, with the help of a tripod and a long exposure, you can blur the people and create some great photographs even when the bridge isn't deserted.
Wide angle lenses will be the most useful here, in order to include enough of the bridge in the foreground.