The Virunga area in the Democratic Republic of the Congo, with over 1 million inhabitants, has to permanently cope with the threat posed by the active Nyamulagira and Nyiragongo volcanoes. During the past century, Nyamulagira erupted at intervals of about every 3 years – mostly in the form of lava flows – at least 30 times. In order to identify a useful tool for hazard assessment at the Goma Volcanological Observatory, we tested VORIS, a freely available software (www.gvb-csic.es).