You will be impressed when you step inside Archbasilica of Saint John Lateran. The floor is a cosmatesque mosaic from the 15th century. The side aisles are adorned with colossal marble sculptures. The gilded paneled ceiling is decorated with artwork and a papal coat of arms. All of these lead your eye towards the sanctuary with a Gothic baldachin containing relics of Saints Paul and Peter. Many also believe the altar is part of a table used by Saint Peter.