Complex sentence: The summit of the mountain has a mosque that is still prayed in by Muslims today, and a Greek Orthodox chapel, constructed in 1934 on the ruins of a 16th century church, that is not open to the public.
Split into simpler sentences: The summit of the mountain has a mosque that is still used by Muslims. It also has a Greek Orthodox chapel, constructed in 1934 on the ruins of a 16th century church, that is not open to the public.