Johan Björefeldt
Google
What an incredible site! Ancient stepped pyramid originally built by the Lima civilization (not the Inca!) in 200-700 AD. The huge pyramid, built by clay bricks, is just a small part of the original structure, meant for religious ceremonies and sacrifices.
You cannot walk around the complex yourself, you need a guide, and there are both English and Spanish speaking tours which are included on your entry ticket. It's a one hour tour, our guide was quite knowledgeable, but we felt the tour in general was a bit rushed. Beside the pyramid itself there's a small "flora and fauna" section showcasing some of the crops and domestic animals (guinea pigs, llamas) of the time. There's also a small indoor museum with a few exhibits by the entrance to the site.
We were lucky to arrive just in time for the last day time tour of the day at 16:40. 15 soles entry per person, but no reservation required. If you come in the evening (I'm sure evening time the pyramid is quite striking!) I believe you do need the reservation.