Between 1903 and 1933 Boissonnas made several trips to Greece where he systematically documented Greece in landscape photographs, taken in all corners of the country reflect its continuity from ancient times to the present day. He travelled to the Peloponnese, Crete, the islands, Ithaca, Mount Athos, etc. On one Greek expedition with compatriot art historian Daniel Baud-Bovy, Boissonnas made the first recorded modern-era ascent of Mount Olympus on 2 August 1913, aided by a hunter of wild goats from Litochoro, Christos Kakkalos.