Inti Raymi is a festival that reverts back to the Inca's. It is a celebration and a sacrifice to the sun of God. While the official ceremony is the 'quote' event, my favorite part was hanging with the locals as they spent the day partying away. This is one of the few events in Peru where the locals outnumber the tourists. Most tourists buy tickets to sit in the grand stands but sitting on the side of the mountain with the locals is where it's at. Main party of the day is in Sacsayhuaman. The biggest festival in the Cusco region with plenty of traditional costumes, lots of beer and even a Llama being sacrificed