Complex sentence: Bergen-Belsen (or Belsen) was a Nazi concentration camp in what is today Lower Saxony in northwestern Germany, located near the hamlet Belsen, three kilometers southwest of the town of Bergen.
Split into simpler sentences: Bergen-Belsen (or Belsen) served as the name of a Nazi concentration camp in what is today Lower Saxony in northwestern Germany. It was located near the hamlet Belsen, three kilometers southwest of the town of Bergen.