- Source: Battle of Angostura (1868)
The Angostura Fortress was a Paraguayan Army fortification, located by the Pikysyry stream (a tributary of the Paraguay river), in Paraguayan territory. The Paraguayan War,[A] (also known as the War of the Triple Alliance[B] and the Great War[4][C] in Paraguay), was a South American war fought from 1864 to 1870 between Paraguay and the Triple Alliance nations (Argentina, the Empire of Brazil, and Uruguay). Angostura Fortress was a battery of Paraguayan defense line fortifications strategically located along Lomas Valentinas. The Paraguayan units surrendered the fortification on 27 December 1868, which were then occupied by Imperial Brazilian Army forces on 30 December 1868. This led to a series of victorious battles won by Triple Alliance armies (also known as December Campaigns).
Further reading
Jacques, Tony (2007). Dictionary of Battles and Sieges: A Guide to 8,500 Battles from Antiquity Through the Twenty-first Century: A-E. Vol. 1. Westport, Connecticut: Greenwood Publishing Group. p. 53. ISBN 9780313335372.