West of the Inter-American Highway, across from Santa Rosa National Park, lies the Guanacaste National Park, a 80,336 acre (32,512 ha) park. The area spans several ecosystems situated in the watershed of the Tempisque and two volcanoes-Orosi (4,879 ft /1,487 m) and Cacao (5,443 ft / 1,659 m). The most recent addition to the massive Guanacaste Conservation Area, Guanacaste National Park was created on July 25, 1989, on Guanacaste Day (Dia de Guanacaste). The park serves as a testament to the hard work of Dr. Daniel Janzen, who lobbied authorities for a park that encompassed a variety of adjoining habitats to improve the survival rates of local fauna. The wildlife corridor the park forms with neighboring Santa Rosa extends southeast to Rincon de la Vieja, forming a broad triangle of protected area.