The Roman Agora is located in the heart of Plaka, next to the Tower of the Winds. It was a vast open space, 110 meters long and 98 meters wide, made to look like a spacious peristyle courtyard, only indoors. The commercial centre of Athens, that used to be housed in the Ancient Agora a few hundred meters to the west, was moved to this specially modified space during the reign of Augustus. It is estimated that the construction of the Agora must have been completed by 10 A.D. 
Today the Agora is only half excavated and only partially open to visitors. It was accessible from two monumental entrances, one of which - commonly known as the Gate of Athena Archegetis - is preserved in very good condition. It has the form of a propylon with four Doric columns (eight meters each) and an epistyle, bearing inscriptions with the names of Julius Caesar and Augustus who gave this monument to the people, as well as a dedication to the patroness of the city, Athena Archegetis. The construction was actually founded by Augustus alone, making it look like Julius Caesar was involved too and the special mention to Athena could be an indication that there was a shrine in her honour somewhere nearby. The Roman Agora was shaped like a great atrium with an Ionian peristyle surrounded by stoas, shops and storerooms. The stores were all assembled on the eastern side of the Agora, and were really just rooms of equal size, sublet by the city. Try to imagine the centre of the Agora as an indoors marketplace that must have looked a lot like today’s street markets. A spring on the south side catered to the people’s needs for drinking water, while the public lavatories were right outside the east entrance. The Roman Agora, contrary to the Ancient Agora of Athens, was built for this purpose from the start, carefully planed and standardized to house the commercial activities of the city.