The only place to see jaguar is the world's biggest wetland, a 170,000km2 floodplain (but sightings are never assured). Jaguars in the Pantanal are twice as big as in the Amazon and encounters are more frequent and stay longer.
The IUCN says that there are about 57,000 jaguars living in Amazonia. This is almost 90% of the total number of jaguars. Still, it's hard to see any kind of animal in the jungle, let alone one as secretive as the jaguar.
Iwokrama is a 3,710km2 tropical forest in the green Guiana Shield that is home to the giant river otter, the Guianan cock of the rock, the black caiman, the huge harpy eagle, and yes, the jaguar.
Jaguars live in a lot of the Pantanal, which is mostly in Brazil (80%) and Bolivia and Paraguay (the other 20%). They are more common to see them in the north. The Oncafari Project, which promotes leisure, watches over wild jaguars..
Cockscomb is the first reserve in the world that was made just to protect jaguars. The refuge was created in 1986, mostly because of the efforts of the famous environmentalist Alan Rabinowitz. It covers 400 km2.
Calakmul is best known for the two biggest mounds in Mesoamerica and the huge Maya city that used to be here. At its peak, the city had about 200,000 people living there.
In a practical sense, Costa Rica is one of the greenest countries in the world. It has over half of its land covered in trees and is home to 5% of the world's species. About 25% of its land is protected in national parks or private areas.