Hadrian's Library

Hadrian's Library is the ruin most people see before they realise it is a ruin. Its tall row of Corinthian columns lines Areos Street just off Monastiraki Square, where crowds pour out of the metro, and many visitors photograph it without ever going in. That is a shame, because behind the facade lies one of the most interesting sites in central Athens. The Roman emperor Hadrian, who loved Athens and lavished buildings on it, created this complex in AD 132 as part of his plan to make the city the cultural capital of his empire. It was not a library in the modern sense but a great rectangular enclosure, with a garden and a long pool in the centre surrounded by a colonnade of about a hundred columns, and on the eastern side halls that held book rolls, reading rooms and lecture spaces. It was, in effect, a philosophy school, a public archive and a place of learning rolled into one. The library was damaged during the Herulian raid of AD 267 and later incorporated into the city's late Roman wall. Then the site kept being reused. In the fifth century a large four-apsed church, the Tetraconch, was built in the courtyard; later came a Byzantine basilica and then a smaller church, and the area remained a busy part of the town through the Ottoman period. Walking around today, you can trace these layers in the foundations, column bases and mosaic fragments, with the Acropolis looming over the southern side. The visit is short and rewarding. Walk along the inside of the western wall to appreciate the scale of the facade, look for the foundations of the Tetraconch in the middle of the courtyard, and find the eastern rooms where the book rolls were kept. Information panels explain the phases clearly. Because the site is right next to Monastiraki, it is easy to slot in between the flea market, the Roman Agora and the Ancient Agora.

Why it is worth paying to go inside: the facade alone is impressive, but inside you understand the ambition of Hadrian's Athens. The enclosure once matched the size of a large city square, and it was decorated with fine marble from across the empire. The library helps explain how Athens survived as a centre of learning long after it had lost its political power: under Roman rule it was still the place where wealthy young Romans came to study rhetoric and philosophy. The later churches built inside show how the city adapted its monuments rather than abandoning them, and the site is one of the clearest places in Athens to see that continuity.

Tickets and hours: Hadrian's Library has its own ticket, ten euros for adults with a reduced rate for eligible visitors, sold at the gate and on the official Hellenic Heritage platform. The old combined ticket covering several sites has been discontinued, so each site is paid separately. From April to August the site is open from early morning into the evening; hours shorten through September and October, and from November to March it closes in the mid-afternoon. Entry is free on certain dates, including the first and third Sundays of the month from November to March. The accessible entrance is on Dexippou Street, about a hundred metres from the main entrance, with a dirt path along the eastern side and adapted toilets on site.

Making the most of it: give yourself forty-five minutes. Pair it with the Roman Agora immediately to the south and the Ancient Agora a short walk west; together they make a superb morning of Roman and classical Athens before the Acropolis in the afternoon. Next to the library, the former Tzistarakis Mosque on Monastiraki Square holds a small collection of Greek folk ceramics. And when you come out, the flea market streets, the souvlaki grills of Mitropoleos Street and the rooftop bars around Monastiraki Square are all within a few steps.