Complex sentence: The site of Checkpoint Charlie, one of the most renowned crossing points of the Berlin Wall, is still preserved and also has a museum, a private venture which exhibits comprehensive documentation of detailed plans and strategies devised by people who tried to flee from the East.
Split into simpler sentences: The site of Checkpoint Charlie, one of the most renowned crossing points of the Berlin Wall, is still preserved. A private museum venture exhibits a comprehensive documentation of detailed plans and strategies devised by people who tried to flee from the East.