Even if you are not an experienced cyclist, I would highly recommend taking a mountain biking trip with one of the tour companies (I went with Eric Adventures - $35.) The views are truly amazing and it is so peaceful to ride in the fields and see the Andes in the background. We rode to two places, Moray (Picture) and the Moras salt mines. I didn't feel comfortable doing the downhill sections so I took the bus for some of the sections. My boyfriend is an experienced mountain biker and he even said the down hill sections were quite dangerous.
Equipment: Bring sunglasses, it's mighty bright out there.
I'm just coming back from a Mountain Bike trip with ECOTREKPERU. Davis, the guide, has shown me some incredible places, and the sensation were amazing !
I did half a day for 25$, but they also told me they organise some longer trips (2, 3...6 days!). One seems crazy : your going downhill from a top mountain (abra de Malaga) to the Jungle...about 5 hours and 3000 meters down !!! Hadn't the time but next time...sure I will !!
Equipment: They provide helmet, gloves and all the biking stuff. Maybe better to have small sport shoes rather than hiking shoes....