According to the Guinness Book of World Records, Prague Castle is the largest in the world at more than 570m long and 130m wide. The castle is built on top of a defensive rampart and has three courtyards, a palace, several churches, multiple gardens, and a monastery. However, Prague Castle does not appear to be a classical castle as constant reconstruction due to wars and fires has produced a disparate assemblage of buildings, representing many different architectural styles and periods including Romanesque, Gothic, Neo-Gothic, Renaissance, and Baroque.
The castle was founded in 880 by Prince Borivoj of the House of Premyslides. The castle initially had a moat and a rampart made of clay and stone. The first stone building was the Church of the Virgin Mary. The Basilica of Saint George was constructed in 920, and the first church dedicated to Saint Vitus, a small Romanesque rotunda, was built in 925.
In approximately 1320, the town of Hradcany was founded in an outer courtyard. Much of the town consisted of palaces of nobles who built their residences as close as possible to the royal palaces to compete for influence. Together with the castle, the area is also called the Castle Quarter.