If you’re in Thessaloniki, even just for the day, the one place you need to visit is The White Tower. It’s the meeting place for many and a symbol for the city.
The tower is part-monument and part-museum. For six euro you can go inside and walk up spiraling stairs to get a birds-eye view of the waterfront and the city. There are six floors (if you’re like me you might need to carry a water bottle if it’s a hot day while you huff and puff up each flight of stairs) and each of them have rooms you can go into, some opening into smaller sections, to learn about the history of Thessaloniki.