Laguna de los Cóndores
aka Laguna de las Momias

This is a beautiful lake, which is worth a visit in its own right. However, most people go for the archeology. Though most were looted, there were over 200 mummies in sealed tombs in the cliff above the lake. Some of the looted mummies were recovered and the remaining ones were taken to the Leymebamba Museum for safe keeping.
Practicalities
This is a ten hour hike each way, and most people rent a horse. Many trekking agencies have treks here. It’s recommended as a three day trek, one day in, the second day at the lake and visiting the tombs and the third day hiking back out.
It’s about a 3 hour drive from Chachapoyas to Leymebamba. From there you start the 10 hour hike to the lake. The campground is only a few minutes walk from the lake. You can rent camping gear in Chachapoyas and do this trek on your own. However, I would recommend going with a local trekking agency. You will learn so much more with an experienced guide than you could on your own.