It provided a natural fortification, but during the retreat, Mexican troops were scattered, making communication difficult.

The Confederates used the low adobe houses in the town as natural fortifications.

It would appear they are developing it as a natural fortification.

No system of terrestrial encampment could equal these natural fortifications.

This natural fortification was used by the Celts, and later the Romans.

Al-Husayn objects to the vulnerable location, deprived of water or natural fortification.

Mount Independence's sheer 200-foot cliffs made it a natural fortification.

The two gorges and the river Rhone to the south provided excellent natural fortifications for the growing town.

I think low kelassium's part of the body's natural fortification.

Sozh's high left bank cut with canyons made a natural fortification.