Perolani is a mysterious waterfall in the valley behind Tocana. From a distance it is impossible to see the base of the falls. Locals say the devil lives there, and the stories are wild: a mule caravan carrying gold was lost at the bottom, a government helicopter nearly crashed trying to investigate, and ex-military jungle trekkers had to abort their attempt to reach it. The mountain face supposedly resembles Darth Vader.
Whether you believe the legends or not, this is genuinely difficult terrain. The waterfall can be seen from the road to Mururata. A side track from the Polo Polo-Tocana road leads to the old Tocana soccer field, the closest accessible viewpoint. If you want to attempt an expedition, go with a guide and leave very early. There is accommodation in Tocana.
For a similar but less risky adventure, try Supay Punku instead.