Athens is full of neoclassical buildings, but some are really amazing. After liberation from Ottomans, Greece was the epicenter of Neoclassicism and Greek Revival concept. Areas like Metaxourgeio, Gazi, even Exarcheia have amazing building that today host museums, galleries and some are private houses as well.
Athens is the must city for architects, especially those who admire Greek Revival concept
Amazing Architectural Tips
Start with Plaka, Kydathineon and Adrianou.
Move to Thisseio, Metaxourgeio and Gazi.