Complex sentence: The original fort was relocated to a different site on the hill in 2003, to accommodate the largest mosque in Uganda, with a seating capacity of 15,000 people, built with monetary assistance from Libya.
Split into simpler sentences: The original fort was relocated to a different site on the hill in 2003 to accommodate the largest mosque in Uganda. It has a seating capacity of 15,000 people, built with monetary assistance from Libya.