Peru's extraordinary natural environment features a wealth of protected areas, wildlife reserves, and archaeological zones. Dozens of national parks and nature preserves make up a bit more than 10% of Peru. The majority of these national parks and nature reserves are undeveloped tropical forests, with few services or facilities available for tourism. Others, however, offer easier access to their wealth of natural wonders. The discussion below is not a complete listing of all of Peru's national parks and protected areas. Rather, it details the ones that are the most accessible and most rewarding for visitors, including several of the largest and most biodiverse on the planet.

Many of them require visitor's permits, for a small fee. If you go with an organized tour, the tour operators almost always take care of the bureaucratic details and include the fees in their package price.

Peru's protected natural areas go by several names in Spanish, according to distinct legal statutes and protections: parques nacionales (national parks), reserves nacionales (national reserves), sanctuarios nacionales/históricos (national or historic sanctuaries), and zonas reservadas (reserve zones), among others.

Manu National Park & Biosphere Reserve

Manu is probably the most famous national park in Peru. Covering nearly a million hectares, Manu National Park & Biosphere Reserve is the second-largest protected area in the country and one of the largest in South America. It is also thought to be the most biodiverse zone on earth. Created in 1973, the park reserve is on the eastern slopes of the Andes within the Amazon basin and comprises an extraordinary variety of habitats, including tropical lowland forest, mountain forest, and grasslands. The reserve zone contains the lower Manu River, the Río Alto Madre de Dios, and a number of beautiful oxbow lakes. About 1,000 bird species -- about a quarter of all birds known in South America and 10% of all species in the world -- and more than 200 species of mammals have been identified. Also found in the park are at least 13 endangered wildlife species, including black caimans, giant river otters, and ocelots. Botanists have claimed that Manu has a greater number of plant species than any other protected area on earth.

Manu is superb for observing wildlife, but trips to Manu are lengthy and costly. Most trips bus travelers in and fly them out by light aircraft. There are very few lodges within the designated reserve and cultural zones, and access to the reserve zone is by organized tour. Independent visits are possible in the cultural zone only.

Giant Otters -- One of the most fascinating creatures that visitors have a chance of spotting in the southeastern Amazon basin in Peru is the giant otter (Pteronura brasiliensis), the largest of the 13 otter species in the world. Hunted for its pelt, it has landed on the World Conservation Union ignominious Red List of Endangered Species and has probably been eliminated in Argentina and Uruguay. It has recovered in Peru, but fewer than a couple hundred probably exist.

Giant otters today are primarily "hunted" by tourists and photographers. The large and very active animals are found in lakes and rivers of tropical lowlands, where they can rather easily be observed. Conservationists are concerned that otters in Manu and Tambopata, among other places, have suffered from human interference in the form of tourist canoes, which leads to long-term changes in behavior and decreases in reproduction. Less invasive observation towers and viewing platforms have been constructed in Cochas Otorongo and Salvador in the Manu Biosphere Reserve. The Giant Otter Project of the Frankfurt Zoological Society (www.giantotterperu.org) is overseeing monitoring and protection of the species in the Pacaya-Samiria National Reserve and the Manu and Bahuaja-Sonene national parks in southeastern Peru.

Tambopata National Reserve

The Tambopata National Reserve is more accessible and less restrictive than Manu. The park is made up principally of lowland forest along the Tambopata River. A number of lodges are in and around the reserve, accessible from Puerto Maldonado. The lodges offer shorter stays but usually include naturalist-led expeditions to remote areas. Independent travel with a guide can also be arranged in Puerto Maldonado. Although Manu is more celebrated and probably more pristine, with greater species diversity, the flora and fauna that can be observed by most visitors at Tambopata are remarkably similar.

Huascaran National Park

Home to a chain of snowcapped mountains that comprise the longest tropical range in the world, the 161km (100-mile) Cordillera Blanca in the central Andes, Huascarán is a mecca for climbers and a host of outdoor and adventure travelers. Its scenery and offerings -- mountain climbing, trekking, horseback riding, white-water rafting, fishing, and mountain biking, among others -- are perhaps unequaled in the Americas. With 200 alpine lakes, 600 glaciers, spectacular mountain vistas, and nearby ancient pre-Columbian ruins, though, Huascarán is also a magnet for travelers who want to appreciate the scenery with just their eyes, not necessarily their legs and lungs.

Named for the highest peak in Peru, the park's altitude ranges from 2,500m to 6,768m (8,202 ft.-22,205 ft.) and includes more than two dozen snowcapped peaks above 6,000m (19,700 ft.). Huascarán is the second-highest park in the South American Andes. Climbing and trekking opportunities range from expert to moderate, with the latter easily managed by anyone in good shape. Arrangements for manageable 2-day walks and 2-week camping hikes crisscrossing the formidable passes of the Cordillera can be easily arranged in Huaraz and Caraz.

For independent treks in the park, a permit must be obtained from the park office in Huaraz. Some locals and foreign visitors have complained that the national park is not being managed as well as it might be, and that trash has accumulated along the major trails.

Machu Picchu Historical Sanctuary

Machu Picchu is much more than the famous Inca ruins carved into a mountainside. The Machu Picchu Historical Sanctuary, named a UNESCO natural and cultural World Heritage Site in 1983, is a designated archaeological zone and 33,000-hectare (81,545-acre) preserve. International concern over environmental damage to Machu Picchu and the Inca Trail led the Peruvian government to introduce more stringent measures to protect the zone's natural heritage, including limits on the number of people allowed on the trail. Proposals that would severely compromise the natural environment, such as the building of cable cars to the ruins, have been defeated, at least for now.

International environmental and conservation groups, such as World Parks Endowment, have been lobbying the Peruvian government to create a large Inca National Park and expand the protected area around Machu Picchu into the neighboring Vilcanota and Vilcabamba mountains, which would establish a major protected area.

Pacaya-Samiria National Reserve

The largest natural reserve in Peru, Pacaya-Samiria is one of the Amazon's (and the world's) richest wildlife habitats. Covering more than 2 million hectares (5 million acres) of pristine rainforest and wetlands in the north-central Amazon region (about 322km/200 miles south of Iquitos), the reserve is difficult to penetrate during the rainy season (Dec-Mar). The reserve is full of rivers and lakes, and it boasts some of the Amazon's most abundant species of flora and fauna.

Pacaya-Samiria is considerably less accessible than the jungle farther north and is much less visited than Manu or Tambopata. Several tour operators now organize river cruises, canoe trips, and camping expeditions, and a couple of native communities are promoting camping trips and immersion experiences. A permit from INRENA, the Peruvian parks authority, is required to enter the preserve.

Paracas National Reserve

South of Lima, in the department of Ica on the southern coast, this peninsula is blessed with an abundance of marine wildlife and seabirds. About two-thirds of the 335,000-hectare (827,800-acre) reserve is ocean; the desert landscape is barren and rather absent of most plant life. The Ballestas Islands, contained within the nature preserve, are rich in bird and sea lion life, and present excellent and very accessible opportunities for viewing wildlife up close.

Note: This information was accurate when it was published, but can change without notice. Please be sure to confirm all rates and details directly with the companies in question before planning your trip.