Complex sentence: Charlie and Phil take their kids to Camp Driftwood, a camp they attended as kids, but once there they discover that Camp Driftwood is no longer the kindhearted camp site of its time.
Split into simpler sentences: Charlie and Phil take their kids to Camp Driftwood, a camp they attended as kids. But once there, they discover that Camp Driftwood is no longer the kindhearted camp site of its time.