Complex sentence: The principal and older part is at the top of the Greensand Ridge overlooking the Vale of Kent, the area known as "The Harbour" is to the South at the bottom of the hill, and many houses here were originally owned by the local authority.
Split into simpler sentences: The principal and older part occupies the upper slope of the Greensand Ridge overlooking the Vale of Kent, while the remainder is located at the bottom of the hill. This area is known as The Harbour and many houses here were originally owned by the local authority.