Very close to one another, from Plateia Navarinou north across Egnatia, stand three major monuments associated with the early-4th century Roman emperor Galerius. The ruined Palace of Galerius sprawls east-west across the square. You can descend into it, or just peer over the handrail. Pieces of floor mosaic, columns and a few walls survive.

Across Egnatia is the Arch of Galerius, featuring sculpted soldiers in combat; it was erected in 303 AD to celebrate the emperor's victories over the Persians in 297.