Thanks to Nasia, who is digging at Paphos this summer! Paphos is a UNESCO site and is commemorated on this 1982 'World Cultural Heritage' cover. The stamp on left is the monogram of Christ, center is the head of King Palaepaphos, and at right is Theseus fighting the Minotaur. The limestone Odeon theater from the site is on cachet. 
First day cancel on stamp with matching postcard front image....almost a maxicard!
Thank you Tiem! More mosaics from Paphos on definitive stamps showing events from Greek mythology.