Forts

The ruins of a military fortification sit atop this mountain.

Beneath the southern end of the Golden Gate Bridge is the “Gibraltar of the West Coast,” a fort built to protect the San Francisco Bay from naval attack.

This coastal port saw one of the most significant battles of the Civil War.

A nearly impregnable 16th-century fort is one of Goa's oldest.

Historic seaside park featuring explorable, abandoned military structures.

This 17th-century Portuguese fort now houses a nautical museum.

This 17th-century fort, built by the Dutch to control a piece of the international spice trade, is now a city park.

Designed as a 17th-century watchtower, the former fort is now a popular sunset haunt.

Despite its extensive history, this fort saw little to no combat.

This former outpost was designed to protect the lucrative fur trade of the 18th century.

A defensive fortification carved into a cliff near Sydney Harbour.

The former home of the army detachment that captured Geronimo.

An interesting look into 18th-century American history.

This colorful gate stands as an entrance to the walled city of Old San Juan.

The ruins of a military outpost from the 1860s form the centerpiece of a Nevada state park.

A 2,000-year-old Iron Age fort offers stunning ocean views.

A colonial-era fort with panoramic views across the border of Timor-Leste, now home to a hotel.