Heidelberg Castle, Germany

Between 600,000 and 200,000 years ago[citation needed], "Heidelberg Man" died at nearby Mauer. His jaw bone was discovered in 1907; with scientific dating, his remains were determined to be the earliest evidence of human life in Europe. In the 5th century BC, a Celtic fortress of refuge and place of worship were built on the Heiligenberg, or "Mountain of Saints". Both places can still be identified. In 40 AD, a fort was built and occupied by the 24th Roman cohort and the 2nd Cyrenaican cohort (CCG XXIIII and CCH II CYR). The Romans built and maintained castra (permanent camps) and a signalling tower on the bank of the Neckar. They built a wooden bridge based on stone pillars across it. The camp protected the first civilian settlements that developed. The Romans remained until 260 AD, when the camp was conquered by Germanic tribes.