Attalos II ruled Pergamon, a Hellenic kingdom in Asia Minor (modern Turkey), from 159 to 138 BCE. Attalos donated this colonnaded building to the city of Athens, where he was educated. The citizens of Athens surely appreciated the respite it provided from the hot sun in the adjacent outdoor Agora where they transacted business, discussed philosophy, and governed Athens. Built around 150 BCE, it’s in excellent shape because it was reconstructed in 1956 CE as a museum. It serves as the headquarters for the ongoing excavation of the Agora, with offices, a library, and a laboratory for conservation of artifacts.