Cusco was the center of the Inca Empire, which rivaled the Roman Empire in terms of size and influence. The Plaza de Armas is the center of Cusco, and everything for visitors is available here. Cusco has the highest elevation of the three areas; at least one hotel in Cusco pumps extra oxygen into its rooms and suites to help alleviate the difficulty of acclimation to the city's high altitude.

While in Cusco, see the Inca Empire's Temple of the Sun, which was converted into a Dominican convent after Francisco Pizarro and his Spanish conquistadors pillaged and plundered the city in 1533. The Dominican convent was part of the order founded in 1534 in Cusco, and the Church of Santo Domingo is archeologically interesting in its own right. In fact, almost all the sites to see in Cusco are Christian churches and cathedrals. The oldest, San Blas, features a beautiful, golden altarpiece and a fresco, dating to the mid 16th century, of the Virgin of Good Event (Virgen del Buen Suceso). The Cathedral is said to have been built, in the 17th century, on the site of the former palace of an Inca ruler. Like San Blas, it is of the baroque style, and well-preserved despite some earthquake damage.

To see some relics from the Inca Empire, a visitor to Cusco should visit the Admiral's Palace's Archeological Museum. The collection of Inca Empire relics include items from all of Peru. There are some post-conquest items, like Colonial tables and chairs, and the Archeological Museum also has a modern section.

The Lost Incan City of Machu Picchu

Machu Picchu is 7,000 feet above sea level, and the high altitude can be rough for anyone who has just arrived in the country. I recommend that visitors start in The Sacred Valley or Cusco, and work their way up to Machu Picchu (after all, it's not going anywhere!) later in the trip. The amazing ruins of Machu Picchu are split into agricultural, religious and residential subparts, where many Incas worked, prayed and lived before Pizarro and his Spaniards arrived, plundered, and basically ended this once magnificent Empire.

Machu Picchu itself was so well hidden -- even today, it's hard to see until you're right next to it -- that the Spanish invaders never found it. Since it wasn't ruined by the Spaniards, it's the best representation of what life was like in the years of the Inca Empire. The llamas casually grazing on the steppes complete the image. The sweeping views of The Sacred Valley from Machu Picchu can instantly transport a visitor; it's easy to imagine this place as it once was.

Two highlights of The Sacred Valley are the Pisac ruins and Ollantaytambo ruins. It goes without saying that the most celebrated ruins of the Inca Empire are in Machu Picchu - which are in the minds of many a real World Wonder - but Pisac and Ollantaytambo are wondrous in their own rights.

The Sacred Valley of the Incas proceeds northwest from Cusco, through the areas of Pisac and Ollantaytambo. The Pisac ruins are comprised of a temple area amid many smaller structures along a mountaintop.

Ollantaytambo is at the far end of The Sacred Valley. Ollantaytambo is fascinating, with well-preserved structures originally built right into a steep mountainside for defensive purposes. The modern town in this ancient part of the world is a popular pit stop for tourists and travelers. People who live here today, call it "the living Inca town" because all of its streets are the same as the original town of the Inca Empire, and many houses still have original Inca walls.