Rio Abiseo is one of Peru's 12 UNESCO World Heritage Sites ... and the most remote. Located in San Martin, between the Marañon and Huallaga rivers, the park covers an area of over 2,745 square km (1,000 square miles).

Rio Abiseo can be accessed from Tarapoto. It is a 3 hour drive to Huicungo, located on the Huayabamba River.

In Huicungo, one then embarks a speedboat to make the beautiful journey upstream along the Huayabamba River to Rio Abiseo.

The scenery along the River Huayabamba soon becomes more dramatic, with much of the area part of a karst system.

Albergue Paraiso Aventura is one of the very few accommodation options in Rio Abiseo. It is basic, but homely.

Visiting some of Rio Abiseo’s waterfalls, such as the spectacular Maquisapa, is a real highlight of a stay in the National Park.

Aside from the dramatic scenery, the other appeal of Rio Abiseo is the abundant flora and fauna.

Transport within Rio Abiseo is exclusively by longboat … or on foot!

There is always plenty of wildlife to be seen along the river banks, including these butterflies sucking minerals on a riverside beach.

There are often rapids that need to be negotiated by the skilled boatmen.

A dramatic example of one of the roughly 5,000 species of flora so far identified in Rio Abiseo.

The ceiba tree is the giant of the Rio Abiseo rainforest, capable of growing up to 70 m (230 ft) in height, supported by large buttress roots.

A wonderful feature of Rio Abiseo is that the jungle hugs the side of the rivers. There has been almost no deforestation.

The limestone geology has led to the creation of numerous caves, such as this one at Quebrada de Churo, which one can enter by first walking and then swimming along the waterway that created it.

Caves such as Cueva de los Franceses can be reached by hiking through the cloud forest, which is a biological adventure in itself.

The loyal boatmen are always waiting upon return from an excursion!

Another of Rio Abiseo’s most spectacular waterfalls is Shihui. One can swim in the pool at the bottom, just as you can at Maquisapa. Wonderful!