In this environment, various species of reptiles such as the American crocodile are especially abundant. The park is very popular for bird watching. It’s also a great place to see monkeys, sloths, jaguars, white-tailed deer, and armadillos. Along with the wildlife, the flora is diverse and there are some rare hardwoods in the park.
According to scientific data, it presents the following records of flora and fauna:
• 480 plant species including trees and shrubs, 14 of which are endemic species and 29 species considered rare and endemic.
• 124 species of reptiles, that is, 53% of the reptile species in Costa Rica (234).
• 112 species of mammals, being 47.8% of the total of these species in the country (237)
• 62 species of amphibians, that is, 32.8% of the 189 species of amphibians in Costa Rica.
• 432 species of birds, 47% of the 931 species reported in the country, considered one of the most important sites in CR for bird watching in its natural state.
In the park, 14 archaeological sites have been excavated, for now not open to the public, belonging to pre-Columbian indigenous occupations. There is, for example, Lomas de Entierro, named in this way for having housed an indigenous cemetery, an important enclave that politically and economically dominated the lower area of the Río Grande de Tárcoles.