We are visiting Thessaloniki which is large metro city. With an 18 year old wondering what we should do with shore time…ship’s shore excursions don’t seem to fit….????
There are some excellent museums.
There are quite a few things to do and see in Thessaloniki, check out the city's website:
https://www.thessalonikitourism.gr/index.php/en/see-do
(I'm currently in Thessaloniki for a few days)