Complex sentence: Crude and simplistic, the fort centerpiece was a 10 by 14 foot (3 by 4 m) shed surrounded by a 7 to 8 foot (2 to 2.5 m) tall palisade fence that was 53 feet (16 m) in diameter.
Split into simpler sentences: Crude and simplistic, the fort centerpiece was a 10 by 14 foot (3 by 4 m) cabin. The cabin was surrounded by a 7 to 8 foot (2 to 2.5 m) tall palisade fence that was 53 feet (16 m) in diameter.