Visit Thessaloniki's Archaeological sites
The ancient forum (dated to the late 2nd or the early 3rd century AD) with squares, porticoes, additional buildings and odeum (293-395 AD), the palace complex of Galerius Maximianus (4th c. AD), the thermae, the hippodrome, the temples and other monuments and moveable finds (among them mosaics of exquisite art) brought to light in excavations and surveys. In the south square, is the famous Stoa of the Idols, which was two-storeyed d lavishly decorated.
The Triumphal Arch of Galerius (Kamara), built in AD 305 to commemorate his military successes in general in the eastern provinces of the Roman Empire.
Visit Thessaloniki's Byzantine monuments
Thessaloniki, with its host of Byzantine monuments (due to it’s significance during the Byzantine period), justifiably is considered an open-air museum of Byzantine art. Wandering through the city, it is worthwhile to see:
The churches of Acheiropoietos (5th century) a three-aisled, timber-roofed basilica, the Holy Wisdom of God (Hagia Sophia) (7th century), the Panaghia (Virgin) Chalkeon (1028), Hosios David (12th century), St Panteleemon (late 13th or the early 14th century), is of four-columned cross-in-square type, Ayioi Apostoloi (1310-1314),Taxiarches (14th century), Panagouda a three-aisled basilica with significant icons, Agios Ioannis Prodromos (Nymphaion),Vlatadon monastery a 14th century foundation of which only the katholikon and two cisterns within the precinct survive, Ayios Demetrios a splendid basilica dedicated to the patron saint and protector of the city, etc.