The Arch of Galerius or Kamara and the Rotonda are neighbouring early 4th-century monuments in the city of Thessaloniki. The Rotonda is also known as the Church of Agios Georgios or the Rotonda of St. George.
The Arch of Galerius was constructed to celebrate the victory of Galerius over the Sassanid Persians. Originally it was an octopylon forming a triple arch but today, only parts of the masonry symbols of the arches survive and three of the eight pillars.
The Rotonda (or Rotunda) is one of the most important Roman monuments in Thessaloniki. It stands just next to the Arch of Galerius in the city centre and it is also known as the Church of Agios Georgios. This cylindrical structure was built in 306 AD by the Roman tetrarch Galerius, who intented it to be his grave. At first, it worked as a temple but it remains unknown to which god this temple was dedicated. This is one of the oldest Orthodox churches and has been included in the UNESCO list of the World Heritage Sites. In fact, all Paleochristian and Byzantine monuments of Thessaloniki were included in this list in 1988.