The Stoa of Attalus was a gift to the city of Athens from the king of Pergamos, Attalus II (159 BC - 138 BC).
It was two-storey, with Doric style, and a length of 115 meters. It had 42 rooms that served as shops. At the north and south ends were staircases leading to the upper floor.
The portico was destroyed by the Heruls in 267 AD.
The gallery was completely restored between 1953-1956 by the American School of Classical Studies in Athens to house the museum of Ancient Agora.
See a digital representation of the ancient market of Athens and the Stoa of Attalos in the video below:
