"For the first time Athens was to grow again"

In addition to the completion of the Olympieion, already mentioned above, Hadrian's embellishment of the city of Athens included the construction of a substantial library complex (completed in 132 AD) with associated public gardens  on the north side of the Acropolis.

The Library of Hadrian at Athens
Public DomainThe Library of Hadrian at Athens - Credit: GreyElfGT