Edward Hume was said to have declared the sight of Ometepe more valuable than the treasure from the just-sacked city of Granada. The volcano is believed to have risen in the early Holocene epoch and, through continual eruptions, now reaches an altitude of making Ometepe the world's highest lake island. Although it went through a long quiet period, on December 8, 1880, Concepción came back to life. This eruption was extensive, and the volcano remained active for a year. More eruptions followed in 1883, 1889, 1902, 1907, and 1924. In 2005, an earthquake measuring 6.2 on the Richter scale occurred as a result of increasing pressure within the volcano. Cracks appeared on roads throughout the island and an advisory to leave the island was issued. This was the first minor eruption since 1999. The most recent eruption was in 2010 and although it was extremely violent, few of the inhabitants heeded the order from the government in Managua to evacuate the island and little damage was done. The southeast half of the island consists of Volcán Maderas, which has a crater lake and supports a diverse rainforest environment. Maderas is also believed to have risen in the Holocene epoch and rises above sea level. It is considered extinct or possibly dormant. The large lagoon in its crater was discovered on April 15, 1930, by the farmer Casimiro Murillo. The sides of the volcano are mainly covered with coffee and tobacco plantations while the remainder is rain forest. Much of this part of the island is now a nature reserve. The volcanic ash has made the soil of this island extremely fertile, allowing continuous planting. The volcanoes are visible from everywhere on the island, and life on Ometepe revolves closely around them. They also play an important part in the myths and legends of the island, which once served as an indigenous burial ground. IUGS geological heritage site In respect of it being 'a type example of volcano spreading and volcano-tectonic interactions in the volcanic arc sedimentary basin of Lake Nicaragua', the International Union of Geological Sciences (IUGS) included 'La Isla de Ometepe: Quaternary volcanoes in the Lake Nicaragua sedimentary basin' in its assemblage of 100 'geological heritage sites' around the world in a listing published in October 2022. The organisation defines an IUGS Geological Heritage Site as 'a key place with geological elements and/or processes of international scientific relevance, used