Sun Gate (Inti Punku): if you've just arrived via the Inka Trail, this will be your first experience of the ruins. Others can backtrack from the ruins along the trail and up the hill. From here you can see back down each valley offering excellent views. It's a fairly strenuous hike (probably 1-1.5 hours each way) but well worth it. If you catch the first bus from Aguas Calientes and head straight here you may be able to reach it in time for sun to peak over the mountain and through the gate.

Temple of the Sun: Near the summit of the main city, the stonework on the temple is incredible. Look closely and you will see that there are a variety of stone walls throughout the city. Most are rough stones held together with mud, the common stone walls found throughout the world. But many buildings or parts of buildings are done with the more distinctive and impressive closely-fit stonework. The temple is the absolute pinnacle of this technology. Observe it from the side, descending the stone staircase in the main plaza.

Intihuatana: A stone carved so that on certain days, at dawn, the sun makes a certain shadow, thus working as a sun dial. From Quechua: Inti = sun, huatana = to take, grab: thus grabing (measuring) the sun. (pronounce 'intiwatana')

Temple of the Condor: The tour guides will try to tell you that this was a temple, but look closely: between the wings of the condor is a chamber with grooves cut in the stone to secure manacles, a walkway behind where a torturer may walk to whip the prisoner's backs, and a scary looking pit to let the blood of prisoners drain. Clearly the condor was a symbol of cruel justice, but a sanitized version is told for the benefit of middle-aged tourists and their children.

Machu Picchu Ruins:
This well preserved site, which measures 32,000 acres and consists of temples, houses, plazas, agricultural terraces, fountains and staircases, is evidence that Machu Picchu is an ancient city. The Machu Picchu Ruins were re-discovered in 1911 by Hiram Bingham. Today, it has been declared a UNESCO World Heritage Center, and it is the most visited site in the country. These 500 year old ruins attract about 2500 visitors everyday and are considered one of the major contributors to Peru's economy.

Huayna Picchu:
For the more adventurous tourists, a trek up Huayna Picchu is a great idea. Huayna Picchu means "Young Mountain" in Quechua, and Machu Picchu means "Old Mountain." Usually two groups of 200 visitors are allowed the climb in a day, so tourists should make their way to Huayna Picchu early. There are cables attached to some of the rocks to enable an easier climb. Although the view from the climb is spectacular, tourists should be fit enough to make the climb. Tourists can choose from coming down by the same route or an alternate one that leads to the Moon Temple.