Visited August 2016.

It is possible to see all inscribed properties in just one day, but you have to start early as some churches are open only from 9am to 11am (Panagia Chalkeon). The most impressive for me was St. Demetrios although its interior looks very new and it’s hard to feel the byzantine atmosphere there. The most beautiful is Osios David/Latomou Monastery. Some of the churches are closed for the public (Christ Saviour). The most beautiful view of the city can be seen from Blatades Monastery and the northern city walls.

I really recommend a guidebook Monuments of Thessaloniki by Nikos Papachatzis in which you will find lots of info about early Christian and byzantine monuments; keeping it in hands while walking through the city you will have a chance to see many details that you would not have noticed without it.