 In 1887, together with Julius Döring, Volters identified the location of Apuolė, the first Lithuanian settlement mentioned in written sources.He also tried to locate Voruta, the presumed capital of King Mindaugas, and the site of the Battle of Saule.In 1888–1889, with funding from the Imperial Russian Geographical Society, he surveyed and excavated more than 210 tumuli near Trakai, Lida, Marijampolė, but did not publish his findings.