The Church of Agios Nikolaos Thon, a declared historical, “preserved monument of the country and a work of art, because it is a remarkable and characteristic example of architecture and art in general of the last century”, with a protection zone about 15 m wide around the church is a pericentric building of a circular plan, from which the niche of the Holy Bema is projected to the north east. The proposed project includes maintenance and restoration work of the monument, thus ensuring the continuity of its presence as a landmark of the center of Athens.