In October 1884, during the Sino-French War, a French fleet sailed to northern Taiwan and attempted to seize both Keelung and Tamsui. At Tamsui, Qing defenders turned back the assault, but Keelung fell. The near-disaster convinced the Qing government that Taiwan's coastline defenses needed fundamental strengthening. Governor Liu Mingchuan was ordered to fortify the Taiwan Strait. He adopted the strategy of "learn from foreigners to defeat foreigners" and employed a German military expert, Lieutenant Max E. Hecht, to help design ten new forts at the estuaries of Penghu, Keelung, Hobe (Tamsui), Anping, and Cihou. Two forts were built at Hobe: Hobe Fort, known as "The Key to the North Gate," and a companion called "Defense of the East." The latter no longer exists.

Governor Liu purchased 31 cannons through the British trading firm Jardine Matheson Holdings -- Armstrong breechloaders from Britain and Krupp breechloaders from Germany. Installation was completed in 1889. Hobe Fort's main barbette held a 12-inch Armstrong and an 8-inch Krupp. The secondary barbette mounted a 10-inch Armstrong and an 8-inch Krupp. The main barbette featured a circular cannon rack allowing full 360-degree rotation, with a firing angle that covered the entire Tamsui River estuary. The sub-walls near each muzzle were cut in concave arcs to provide trajectory clearance. Shell-shaped fillisters along the walls held ammunition stockpiles. The fort was a serious piece of military engineering, designed by a German professional and armed with the best artillery money could buy from two industrial powers.

The fort's architecture reflects its Western design pedigree. The main walls were built with iron cement, reaching a maximum thickness of 4.2 meters and height of 7 meters. An outer earthen wall, 6.5 meters high, served as both shelter and camouflage, with a trench between it and the main wall functioning as a dry moat. The barracks roofs were covered in a layer of soft soil designed to absorb the impact of incoming shells -- an early form of blast protection. Ventilation holes perforated the soil covering. Internal corridors connected barracks and ammunition depots, allowing soldiers to move between positions without exposure. The entire complex was designed so that the single southeastern entrance could be defended by a small force while the outward-facing batteries engaged enemy ships.

Hobe Fort never fired its cannons in war, and that quirk of history is the reason it survives nearly intact. During the Japanese colonial period, the Imperial Japanese Army removed four cannons and converted the grounds into an artillery practice field. After 1945, Nationalist troops were stationed there. In 1985, the Ministry of the Interior designated Hobe Fort a National Level 2 Ancient Monument. Today it is classified as a National Monument. The barracks that once stood in the Central Square are gone, as are the original guns, but the outer walls, vaults, and gate remain close to their original condition. The vaults now house a museum about the French landing at Tamsui -- the very event that inspired the fort's construction. Visitors pass beneath Liu Mingchuan's inscription on the way in, a governor's promise of coastal security carved in stone and kept, ironically, by the absence of the war it anticipated.