MONUMENTA is a civil non-profit company aiming at the protection of the natural and architectural heritage of Greece and Cyprus. Established in 2006, MONUMENTA’ s activity consists of, among others, research and educational programmes, interventions for the protection of sites and historical buildings and public awareness campaigns (guided tours, public discussions, e-magazine, book publications). MONUMENTA’ s pivotal initiative launched in 2013 and focused on the recording, documentation and designation of all the surviving or demolished, 19th & 20th century (1830-1940) buildings of Athens. In this context, hundreds of oral histories have been collected along with accompanying documents ( i.e. photographs, files, architectural plans). All the above findings constitute a precious knowledge repository for historical buildings.