If you need directions here, try asking for ee kamara (the arch), which is what Thessalonians call this hefty monument built by Galerius around A.D. 305 to celebrate a victory over the Persians. Originally, the arch was even larger: Almost half -- another entire arch -- is missing. Look for the Persians, some in the peaked caps and trousers that the Greeks and Romans found so effeminate and absurd, in the carved panels that tell the story of Galerius's battles. Until 1953, the tram line ran under this arch. Air pollution steadily erodes many sculptural details. You can take this place in with a glance, or spend a pleasant half-hour admiring the detail.