Iquitos:

Iquitos, on the banks of the headwaters of the Amazon River, is the most important city in the Peruvian Amazon Jungle. It is advisable to spend some days in one of the different lodges, built in the style of the area, that are found on the banks of tributaries in the jungle. There you may visit indigenous tribes, take walks in the jungle and appreciate the varied flora and fauna.

Altitude: At sea level
Maximun and minimun temperature: 38°C / 18°C
Language: Spanish, its easy find people speaks english and other european languages.

Pucallpa:

Pucallpa is a tourist attraction, have interesting places close by. Just 7 kilometers away is Lake Yarinacocha, where the native community of San Francisco resides. Also close by is Aguatya, where there are waterfalls and a beautiful lake. Pucallpa is the capital of the Ucayali region and has more than 200,000 citizens.

Altitude: Pucallpa is 155 meters above sea level.
Language: Spanish

Manu:

Manu park is situated in southeast Peru, located near to Puerto Maldonado. Access is easier and cheaper from Cusco, is one of the most important tropical parks in the world, and was declared a "World Biosphere Reserve" by UNESCO in 1977. It is home to many different ecological zones between 4,000m (13,120ft) and 300m (984ft) above sea level. Manu harbors a unique variety of wildlife. Over 1000 species of birds, 200 species of mammals, many reptiles and 10% of all the plant species on the planet have been recorded within the park's boundaries.

Altitude : 300 - 4000 msla
Language: Spanish