A restoration of the Roman Colosseum’s southern piazza has been completed after four years of construction, according to Artnet News. The project, led by Stefano Boeri Interiors, has recreated the travertine-paved pedestrian plaza outside the amphitheater’s southern façade, where spectators once waited to enter the arena.

Built between 70 and 80 CE, the Roman Colosseum remains one of the engineering marvels of the world. At four stories high and with 80 arched entrances, the amphitheater could seat 50,000 or more people, equal to a modern stadium. Even more impressive, it was completely freestanding, supported by a complex vault system.