A good budget option, about 15 minutes before Explorer’s Inn [1], is Inotawa (tel. 082/57-2511, www.inotawaexpeditions.com [2], three days/two nights US$240–230 pp), which has a main thatched building with open-air rooms and single beds with mosquito net covering. Bathrooms are shared, with flush toilets but no hot water.
There is a small bar, a restaurant with vegetarian food, and an option to visit the clay lick near the Tambopata Research Center [3].
Inotawa offers two- to five-night, lodge-based and expedition trips and is 3.5 hours upstream from Puerto Maldonado [4].
Links:
[1] http://www.moon.com/destinations/peru/the-amazon/puerto-maldonado/jungle-lodges/rio-tambopata-lodges/explorer-s-inn
[2] http://www.inotawaexpeditions.com
[3] http://www.moon.com/destinations/peru/the-amazon/puerto-maldonado/jungle-lodges/rio-tambopata-lodges/the-tambopata-research-center
[4] http://www.moon.com/destinations/peru/the-amazon/puerto-maldonado