Pilpintuwasi is located on the Nanay riverside near the village Padre Cocha, about a 20 minutes boat ride from Bellayista. I took the public boat at 3 soles each way; you can take a privet boat for 30 to 50 soles round trip. Once on the island you can walk the 15-20 minutes or for 1 soles take the island transport moto-taxi. That is what I did both ways, when it is hot or raining you will appreciate it. I also recommend eating lunch on the island before heading back. You do need a guide and the fee for the park is 20 soles for adults and 10 for students.
I was delighted to be greeted right away buy a group of Huapo Rojo or Red Uakari monkeys they are rare and can only be found in the Amazon.