Well, the obvious is Machu Picchu. The place is indescribable. When you first see it, the view is breathtaking. There are two ways to get there. You can hike in from Cuzco. That takes about 4 days and you see a lot of scenery and ruins along the way. Or, you can take the train. Both have advantages and disadvantages. Taking the train allows you to do it all in one day. Unless they have fixed the road or the tracks, it's also something of an adventure because the tracks were washed out as well as much of the road to the temporary station and it is now a very narrow dirt track. If you hike, you get to see a lot of country by hiking in but the first view of Machu Picchu is from a considerable distance, so it somewhat lessens the drama of seeing it the first time. By taking the train, you can get the most dramatic "first glimpse".
Cuzco is a great city to sightsee also. It was the Inca capital and there are still significant ruins in and around the city. There are a lot of early colonial buildings also.
Lima is a dump. The place looks grimy, even from the air. Traffic is a nightmare.
As for pooning in Peru, there are some local legends who can help you get, pardon the pun, the lay of the land. I understand the price/quality ratio is quite good and there are some stunning women available.
