Rampart (noun)

1. A defensive wall of a castle or walled city, having a broad top with a walkway and typically a stone parapet.
2. A long, broad embankment or fortification built as a defense against attack.

Origin:

Late middle english: from old french rempart, from re- (expressing intensive force) + emparer "seize, take possession of", from latin impetrare.

Examples:

1. The castle was protected by a rampart.
2. The ancient city was surrounded by a rampart.
3. The rampart provided a great view of the surrounding countryside.
4. The rampart was built to protect the town from invasion.
5. The rampart was a great place to take a walk in the evening.