A small blockhouse and casemate are located to the south of the main fortification.

The next morning, he sent Confederate skirmishers through a dense fog to a ravine within 800 yards of the main fortifications.

The main fortification was built by the British at the outbreak of the American war of independence.

After 1685, the city's main fortifications were begun taking 24 years to complete.

The main fortifications will embrace the entire perimeter.

You describe these as the main fortifications.

The village was rebuilt, though without the main fortifications.

Like his mini-fortresses, where you leave a sallying force outside the main fortification.

The railway guns also fired a few rounds at the main fortifications and rail lines, but most missed by some distance.

Sixteen rectangular classrooms, covered with arched ceilings, were built along the main fortifications.