Paris has the Eiffel tower, Rome has the Colosseum, and Prague has the Charles Bridge (KarlЕЇv Most). It is at once a historic site and an attraction, a hundred-pictures-worthy point and a heavy-laden Middle Ages wonder. The construction officially started in 1357, when Charles IV, dissatisfied with wooden bridges burning down or wrecking in floods, commanded the young architect of the St. Vitus Cathedral to build a new solid one, made of stone this time. The numerous baroque statues were added by the 17th century, giving the symbol of Prague its spectacular wondrous look and at the time symbolizing the triumph of Catholicism in Bohemia. Most statues have been replaced by copies, and only a handful standing today are still the original ones. You can spend hours examining only the statues themselves.
Taking in an oddly harmonious blending of Gothic and Baroque styles that the Charles Bridge represents, let alone observing the surroundings adds up to a considerable amount of time typically spent on the Bridge, which explains the throngs of tourists hanging around day and night. Even at the darkest hours, even at dawn you are not likely to be alone taking photographs of the Prague Castle, the St. Vitus Cathedral and other views, which are truly spectacular, especially at night, when all the buildings are illuminated.
The Old Town bridge tower, from where the construction of the bridge had began, offers an even more breathtaking view of the city for only 50 koruna (less than 3 dollars). Unfortunately, it is only open during the day. The summer closing hour, however, is 10 pm, so you just might catch a perfect sunset shot from there. There are some surviving sculptures, both originals and copies, that face the Old Town and are worthy of a close look.