Fort San Domingo is Tamsui's most famous sight. The original fort, built in 1628 during the Spanish occupation of Taiwan (1626–41), was dismantled by the Spanish before they left. The 13m-high structure seen today is the Fort Anthonio built by the Dutch in 1644. These days the original Spanish name is used, though to locals it's still the Red Haired Fortress (a reference to the colour of Dutch hair).
The fort was under Chinese control from 1683 to 1868 when the British leased it, painted it red and made it their consulate.
The admission fee includes entry to Hobe Fort and the Customs Officer's Residence. The fort is closed on the first Monday of the month.