The later Roman era, after Pausanias, has left Greece (especially the south) with few significant buildings but with tremendous destruction. Where the Herulians already managed to reduce large parts of Greece to ashes in the mid-3rd century (in Athens only the Acropolis was actually spared, after which a new wall in Athens was to protect only a miniscule part of the old city), once again the Goths ( in the 4th century) destroyed many parts of Greece.
Alaric’s march in the 4th century was originally aimed at Constantinople, but when he failed to do anything there, he moved south through Thessaly and the pass at Thermopylai into Greece. After some time he broke off the siege of Athens (he thought he had seen the goddess Athena walking over the walls with helmet, shield and spear), after which he was welcomed by the population and even offered a tour of the city. He then directed his raids towards Eleusis (which he totally destroyed: the Mysteries would never be celebrated again) and the Peloponnese, where he captured the major cities (Corinth, Argos, and Sparta) and sold much of the population into slavery. Eventually he managed to escape to the north of Greece with most of his booty, and was even appointed magister militum per Illyricum (commander of the cavalry in Illyria) by the emperor of the Eastern Roman Empire, a title that conferred the desired respect on him from the emperor, in addition to the right to supply his men at the expense of the imperial stores of food and weapons.
Of course, in typical Roman buildings after Pausanias, we must first of all refer to the triumphal arch in Thessaloniki, with its typical Roman scenes of soldiers, vanquished enemies and a triumphant emperor (who got a victory-wreath on the head by an eagle, symbol of Iuppiter-Zeus).
The Triumphal Arch of Galerius (297), erected after a victory over the Persians, as part of a much larger complex. Drawing: the Galerius arch from 1755.