Castillo de San Cristóbal in Santa Cruz de Tenerife was the first significant fortification on the island, constructed beginning in 1575 and entering service in 1577. Though demolished in 1928 to expand the city, the castle's perimeter walls remain accessible through an underground gallery beneath Plaza de España, discovered during a 2006 renovation. The fortress holds historical significance as the site of Admiral Nelson's defeat in 1797, with the famous Tiger Cannon preserved at the location, offering insights into the region's military heritage and strategic importance.
