The construction of the arch began in 131 AD, when the local authorities wanted to celebrate the arrival of the Roman emperor Hadrian and thank him for his benevolence to the city. The architect and builders of the arch are still unknown. Its location is not accidental, but rather symbolic. In fact, it was strategically chosen to mark the border between the ancient part of Athens and Hadrian's new city. Made of fine Pentelic marble, this arch is 18 meters high, 12.5 meters wide and 2.3 meters deep.→