In the latter half of the 1st century, the Roman market of Athens was constructed, to shift the city's commercial activities from the ancient market, establishing Athens as a Roman-era economic hub. Julius Caesar and Augustus sponsored this edifice, their names inscribed on the western propylaea. This 111x98m building encloses a spacious rectangular courtyard encircled by Ionic-columned arcades, shops, and storehouses. It features two gateways, with the west gate, known as the "Archegetidos Athena Gate," still preserved in the Doric style. East of the Roman Agora stands the "Aerides," officially named the Clock of Andronikos Kyristos or Tower of the Winds. Constructed by the astronomer Andronikos from Cyrus, Macedonia, in the first half of the 1st century AD, it's the world's oldest meteorological and horological station. This octagonal Pentelic marble tower with a conical roof depicts the eight winds and sundial rays, with an interior hydraulic clock powered by water from the Acropolis. Over centuries, the tower was repurposed as a temple, church bell tower, and Dervish lodge. It was partially buried and later fully excavated by the Hellenic Archaeological Society. Ticket: €8 From 01 November to 31 March; Winter: 08:00 – 15:00 Last entrance: 14:30 From 1 April to 31 October: Summer: 08:00 – 20:00 Last entrance: 19:30 Free entrance days: 6 March - Melina Mercouri Memorial Day 18 April - International Day for Monuments 18 May - International Museum Day The last weekend of September each year (European Days of Cultural Heritage) October 28