Fort of Coimbra, Fortress in Forte Coimbra district, Corumbá, Brazil.

The Fort of Coimbra stands on the right bank of the Rio Paraguai, above the São Francisco Xavier strait. Its irregular star-shaped plan, drawn in 1797 by engineer Ricardo Franco de Almeida Serra, has walls with embrasures following the slope, two horizontal batteries with eight gun ports facing the river and eight facing land, and a ditch on the southwest side. A chapel, powder house and troop barracks stood inside.

Founded on 13 September 1775 as the Presídio de Coimbra, the fort was rebuilt from 1791 in stone and lime under engineer Ricardo Franco de Almeida Serra, whose 1797 plan gave it an irregular star-shaped trace. In September 1801 a 600-man Paraguayan force under Lázaro de Ribera besieged it for ten days, from the 16th to the 25th, and its 42 defenders held out. On 27 December 1864, in the War of the Triple Alliance, Paraguayan colonel Vicente Barrios summoned the fort to surrender with 3,200 men and twelve rifled cannon.

The fort displays Portuguese military design adapted to South American conditions, showing how European eighteenth-century fortification ideas were adjusted for the region. Visitors can observe the stone walls and gun positions that reveal this architectural approach.

A visit requires arrangements through tour agencies in Corumbá because the fortress is only reachable by water. The journey combines a long boat ride with guided tours exploring the fortification.

The fortress holds 31 original artillery pieces from the colonial period, though only 12 remained operational during the Paraguay War. This collection of guns offers insight into the armament and combat capacity of the original garrison.