Cosigüina is a low basaltic-to-andesitic composite volcano that is isolated from other eruptive centers in the Nicaraguan volcanic chain. The 872-m-high stratovolcano forms a large peninsula extending into the Gulf of Fonseca at the western tip of the country. Cosigüina (also spelled Cosegüina) has a pronounced somma rim on the northern side; a young summit cone of Cosigüina rises 300 m above the northern somma rim and buries the rim on other sides. The younger cone is truncated by a large elliptical prehistorical summit caldera, 2 x 2.4 km in diameter and 500 m deep, with a lake at its bottom. Lake filled 90% of the crater, other 10% of vegetation.
Lava flows predominate in the caldera walls, although lahar and pyroclastic-flow deposits surround the volcano. In 1835 Cosigüina was the source of a brief, but powerful explosive eruption that was Nicaragua's largest during historical time. Ash fell as far away as México, Costa Rica, and Jamaica, and pyroclastic flows reached the Gulf of Fonseca.
207 km from Managua or 70 km from Chinandega to Cosiguina. only 45km in pavimented road. By bus takes aprox 2 hours, $4 round trip.
Trails start in the MARENA's office, 5 hours to the summit... many people "non-hikers" goes in 4x4 vehicle, car can reach a half of the volcano. from this point around 1.5 hours to the crater.
My own site