Thessaloniki is the second largest city in Grecce , and the capital of  the CentralMacedonia region.At about a million inhabitants, it is considered Greece's cultural capital, renowned for its festivals, events and vibrant cultural life in general and has recently been ranked by Lonely Planet as the world's fifth-best party city worldwide. More importantly, it is also a city with a continuous 3,000 year old history; preserving relics of its Roman, Byzantine, Ottoman past and of its formerly dominant Jewish population. Many of its Byzantine churches, and a whole district of the city in particular, are included in UNESCO's World Heritage list. 

Places to visit : 

1)White tower(Leukos pyrgos)
2)Archeological museum of Thessaloniki.
3)Museum of Vyzantine History.
4)Momentum of the Alexander the Great.
5)Cinema museum and Photo's museum.
6)The Agia Sofia church.

Things to do:

Nightlife: The city has always been known between Greeks for its vibrant city culture, including having the most cafe's and bars per-capita than any other city in Europe and as having some of the best nightlife and entertainment in the country, thanks to its large young population and multicultural feel. Trendy bars are scattered throughout the city and cater for all tastes, with many located on pedestrianized streets or along the coast, with sea views; while daily happenings and events take place throughout the city everyday. 

Spa:Thessaloniki is famous for it's Spa or Hammam.

Yachting: The Thermaic Gulf is a challenging place for yachting and sailing. Many days there are strong North winds but with low waves, making sailing a fun and joy for all sailors. There are three sailing clubs in Thessaloniki and world championships take place in the city every year. Thessaloniki has several marinas, most notably in Kalamaria, southeast of the city center, while a new one is proposed to be constructed right at the city center that will contain 182 mooring places. There are also many Yacht charter companies renting sailing yachts.