Complex sentence: Ilsenburg is a town in the district of Harz, in Saxony-Anhalt in Germany, situated under the north foot of the Harz Mountains, at the entrance to the "Ilsetal" valley of the small "Ilse" river, a tributary of the Oker.
Split into simpler sentences: Ilsenburg is a town in the district of Harz, in Saxony-Anhalt in Germany. It is situated under the north foot of the Harz Mountains, at the entrance to the "Ilsetal" valley of the small "Ilse" river, a tributary of the Oker.