In 1957, Aris Konstantinidis was re-employed by the Greek National Tourism Organisation and appointed head of the Department of Architectural Studies. His first project in this role was the design of the dressing rooms for the actors performing at the ancient theatre of Epidaurus during the ancient drama festival, where he introduced an early example of his future architectural style. As he described:

“At Epidaurus I left the stones on the walls unplastered, as if I had built a dry, stone wall. [...] The natural texture of the stone [...] together with the concrete [...] which I had also left exposed to show its natural colour and as it had come out of the wooden molds [...] ‘composed’ a plastic form and shape that looked as if it had grown out of the ground. [...] And in this way, the modern building stood naturally in the ...ancient landscape [...] which helped me to ascertain and …realise -almost through a ...metaphysical insight- how well stone, a natural material, can stand ‘naked’ next to concrete, an artificial one.”

In 1960, he designed, three independent tourist guesthouses in a short distance from the theatre, maintaining the same spirit in his design. In 1962, he expanded the GNTO guesthouse complex with four additional buildings. The landscape of Epidaurus seems to have been pivotal for Konstantinidis’ architecture. Referring to Henry Miller’s The Colossus of Maroussi, he wrote that he always kept Epidaurus’ landscape in his heart like a musical score of Mozart’s music.

The GNTO guest houses in Epidaurus are built in the lush landscape of the archaeological site, at close proximity of the ancient theatre. They have a capacity of 24 double rooms, and on the days of the festival, they are served by the café-bar and the restaurant housed in the tourist pavilion.