I can be subjective because i am inloved by salonic but regard religious sites range is a fantastic city,this town have a magic touch.main atracttion in agia sofia square is the agia sofia church.inside is relic of saint basil former bishop of the city.you will see the level of churches in town is under actual level of streets because are very old so try to find hidden gems all over the place,look eaven in holes made for future subway and you will be amaized. Back to agia sofia square..... When you look at the church at the right side of the square,walk along sidewalk and you will see a hole in ground,is another church of Ioannis prodromos or saint john.have visiting hours and must get down on a long stair after a small iron gate.is a tiny lovely yard with a baptisterium.the surprise is inside this small church and specific under it.there are tunnels like cathacombes full of icons.is a must dont miss it.....