Four kilometers from Caraguatay, on the now-gentle Yhaguy River, lie the remains of Paraguay's last fleet from the War of the Triple Alliance. Iron hulls, boilers, artillery pieces and replicas are displayed outdoors in a park of about 54 hectares, with information panels telling the story. Caraguatay, founded on September 24, 1770, keeps old mansions and well-kept streets; on the way, Isla Pucú recalls the Battle of Ka'aguy Juru, fought on that same August 18, 1869.

In 1869 the last steamships of the Paraguayan navy sailed up the Manduvirá and Yhaguy rivers, fleeing the Allied advance. On August 18, 1869, on Marshal López's orders and to keep them out of Brazilian hands, they were set on fire and sunk. Recovery work began in 1978; the salvaged vessels include the Anhambay (captured from Brazil on January 6, 1865), the Río Apa, the Piraveve, the Salto del Guairá, the Yporá and the Paraná.