Complex sentence: Although now there is nothing left of the fortifications the area which was once the fort is still referred to as "Fort" and the area out side the fort; "Pettah" or "pita-koutuwa" in Sinhalese which means outer fort.
Split into simpler sentences: Although now there is nothing left of the fortifications, the area which was once the fort is still referred to as Fort. The area outside is Pettah or "pita-koutuwa" in Sinhalese which means outer fort.