Martello towers are named after a similar 18th-century structure at Mortella Point in Corsica, though this fort predates the standard British models.
The island where the fort sits was once used as a graveyard for Dutch soldiers and is locally known as 'Pulau Keramat' or Sacred Island.
The structure is built primarily from red brick and coral, common construction materials for colonial buildings in the region at the time.
The circular design was specifically chosen to offer 360-degree coverage for artillery, eliminating blind spots in the defensive perimeter.
Kelor Island, the site of the fort, has significantly diminished in size over the decades due to rising sea levels and coastal abrasion.
The fort complex originally included auxiliary buildings that have since been reclaimed by nature or washed away by the sea.
Benteng VOC Martello is a historical Dutch colonial circular fortress located on Kelor Island in the Thousand Islands archipelago of Jakarta. Built in the 17th century by the Dutch East India Company (VOC), the fort served as a defensive outpost to protect Batavia from naval incursions. The structure is characterized by its distinct, thick masonry walls designed to withstand cannon fire. It functioned primarily as a military surveillance point and artillery battery during the VOC's operational years. Today, the ruins represent a rare example of Martello-style military architecture in Indonesia. The site has undergone various preservation efforts to stabilize the remaining brickwork against coastal erosion. It remains one of the few physical remnants of the colonial-era naval defense strategy in the Java Sea.
The north-facing side of the fort where the circular curvature of the walls remains most intact against the backdrop of the sea.
Wear sturdy footwear as the island's terrain is uneven, sandy, and filled with old masonry fragments.
Bring sufficient drinking water and sunscreen, as there are no shops or shade structures on the island.
Visit during low tide to safely access the perimeter of the island and observe the foundation of the fort.
Do not attempt to visit during the monsoon season (December-February) when high waves make small boat travel in the Thousand Islands dangerous.
Respect the site as a historical monument by not climbing on the aging brick walls or removing any stones or debris.
