The worldwide aviation extension, the Marshal Plan resources in combination with GNTO funding and the high quality hotel infrastructure, showcased a significant number of Travel Agencies in Greece. By 1956 only 17 Travel Agencies were operating in Greece. By 1950-1969 their number increased enormously. As a consequence, Greek Travel Organisers have rallied under dynamic collective entities, such as HATTA (Hellenic Association of Travel and Tourist Agencies), established in 1928-1930, as well as SKAL Club, established in 1932. Among the most significant pioneers, were, Thomas Cook, Ghiolman Bros., Varvias, ABC-BELL, HORIZON, Hermes en Greece, Key Tours, Karagiannidis, OLYMPUS, VELOS HELLAS and many more.
Marianna Tsigaridou Krontiri , Travel Guide