What Wikipedia says

Thessaloniki is the second-largest city in Greece and the capital of the administrative region of Central Macedonia. The Thessaloniki Metropolitan Area population in 2011 reached a total of 1,104,460 inhabitants.

The city of Thessaloniki was founded in 315 BC by Cassander of Macedon. An important metropolis by the Roman period, Thessaloniki was the second largest and wealthiest city of the Byzantine Empire. It is a popular tourist destination in Greece: in 2014 Financial Times FDI magazine declared Thessaloniki as the best mid-sized European city of the future for human capital and lifestyle.

Today, the city center of Thessaloniki includes the features designed as part of the plan and forms the point in the city where most of the public buildings, historical sites, entertainment venues and stores are located. The center is characterized by its many historical buildings, arcades, laneways and distinct architectural styles such as Art Nouveau and Art Deco, which can be seen on many of its buildings.

Also called the historic centre, it is divided into several districts, like Ladadika (where many entertainment venues and tavernas are located), Kapani (were the city's central city market is located), Diagonios, Navarinou, Rotonta, Agia Sofia and Ippodromio, which are all located around Thessaloniki's most central point, Aristotelous Square.

Thessaloniki is regarded as the cultural capital of the country. It is renowned for its major shopping streets and lively laneways. The city has long been known in Greece for its vibrant city culture, including having the most cafes and bars per capita of any city in Europe; and as having some of the best nightlife and entertainment in the country. Because of the city's rich and diverse history, Thessaloniki houses many museums dealing with many different eras in history. Two of the city's most famous museums include the Archaeological Museum of Thessaloniki and the Museum of Byzantine Culture. Thessaloniki is also home of a number of festivals and events. The Thessaloniki International Trade Fair is the most important event to be hosted in the city annually.

Thessaloniki is home to a number of prominent archaeological sites. Apart from its recognized UNESCO World Heritage Sites, Thessaloniki features a large two-terraced Roman forum featuring two-storey stoas dug up by accident in the 1960s. The forum complex also boasts two Roman baths, one of which has been excavated while the other is buried underneath the city. The forum also features a small theater, which was also used for gladiatorial games.