The Arch of Galerius is Thessaloniki's most recognizable Roman monument, and one of the city's most popular destinations among locals and tourists. It was commissioned as a monument by Emperor Galerius to celebrate the victorious campaign against the Sassanid Persians in 298 AD and their capture of their capital It is considered the best example of Roman architecture in the fourth century AD, as it includes exquisite marble panels in each of its columns, along with impressive carved decorations. The Arch is one of the highlights of Thessaloniki, where tourists and locals take souvenir photos next to it and learn about Greek architecture and ancient Greek history.