The fort changed hands through force, diplomacy, and sheer persistence. In 1640, the Dutch allied with King Rajasinhe II of Kandy and besieged the Portuguese garrison. A force of roughly 2,500 Dutch troops under Commodore Coster captured the fort that year, and the Sinhalese king's cooperation proved decisive -- though the partnership did not last. The Dutch immediately set about remaking the fortifications in their own image, adding bastions named for celestial bodies: Sun, Moon, Star, and Aurora. Fortifications continued to expand into the early 18th century. When the British took control in 1796, they saw no reason to rebuild what already worked. They opened a new Main Gate in 1873, between the Moon and Sun Bastions, to accommodate Galle's growing role as the administrative capital of the south. Each occupier left their mark on the walls without erasing what came before, creating a palimpsest of colonial engineering.

The Dutch were practical builders. They used cabook -- blocks of coral stone quarried from the reef -- for the massive walls, then paved interior floors with granite and topped the whole structure with thick plinth walls. The architectural ambition went beyond defense. A baroque Protestant church, the Groote Kerk, was planned by Abraham Anthonisz and completed in 1755 to serve both Dutch colonists and newly converted local Christians. The Commandant's residence, the arsenal, and the gun house were the most prominent buildings, but the fort also contained workshops for carpentry, smithing, and rope-making -- a self-contained economy behind walls. Perhaps their most ingenious contribution was an elaborate sewer system designed to flood at high tide. The ocean itself carried waste out to sea, a solution elegant enough that it functioned for centuries. The fort's layout followed a rectangular grid, with peripheral roads running parallel to the ramparts and interior streets lined with low Dutch houses featuring gables and deep verandas.

UNESCO inscribed Galle Fort as a World Heritage Site for its unique demonstration of how European architecture and South Asian traditions interacted from the 16th to the 19th centuries. That interaction is visible not just in the buildings but in the people who still live inside them. More than half of the fort's residents are Sri Lankan Moors, descendants of the Arab and Persian traders who used Galle's harbor long before any European arrived. Sinhalese, Tamil, and families tracing their ancestry to Dutch, Portuguese, German, and English settlers share the same narrow streets. Mosques stand within sight of churches. The Meeran Jumma Mosque, with its gleaming white facade, and All Saints' Church represent different centuries and different faiths occupying the same few hectares of fortified ground. This multicultural character is not a recent development or a tourist attraction -- it is the continuous thread that has run through Galle Fort since its earliest days as a trading post.

On December 26, 2004, the Indian Ocean tsunami struck Galle with devastating force. The modern town outside the walls suffered catastrophic damage. Inside the fort, the massive Dutch ramparts absorbed much of the wave's energy. The walls that had been built to withstand naval bombardment turned out to be effective against a very different kind of assault. Damage occurred -- the National Maritime Museum near the Old Gate, established in 1992 to house artifacts from more than twenty-one shipwrecks discovered in Galle Harbor, required repairs. But the fort's fundamental structure held. In the years since, restoration efforts have continued, overseen by the Archaeological Department of Sri Lanka. The Old Dutch Hospital was reopened in 2014 as a dining and shopping precinct, and the Dutch-period museum inside the fort offers visitors a detailed account of each building's layered history. The fort endures not because it was frozen in time, but because each generation found a new reason to maintain it.