Prague Castle. The biggest ancient castle in the world, according to the Guinness World Records, which rises above the city offering beautiful views of the areas below. Also on site is the St. Vitus Cathedral with its lookout tower, the Castle Picture Gallery, several palaces and museums and the beautiful Royal Garden, among other attractions. You can also watch the Presidential Guard, and the changeover of the guards on duty on the hour. The entrance for St. Vitus Cathedral is free, but the queue may be long (1 hour). A Prague castle ticket is 350 CZK and audioguide a further 350 CZK. This is a large amount for an audioguide, but it lets you skip the St. Vitus queue. Do not confuse this Prague Castle which dominates the city and is in the Hrad?any area with Prague Castle Blahutovo which is in the Kbely suburb.