Roman Military fort – Porta Praetoria, Regensburg

179 a.D. is the birth year of Regensburg as a Roman military fort was errected unter emperor Marc Aurel. The Danube was the natural border of the roman empire and Regensburg was a strategical point to settle with an enormous army (over 6000 soldiers) on the most northern banks of the river. The P. P. is the only remaining gate to the fort out of four.