7. Machu Picchu

Most seasoned travelers agree that Machu Picchu is the world's most dramatic ruins. It sits boldly perched on a steep sided mountain saddle far above the partially encircling Urubamba River gorge.

What remains of the precision stonework of the pre-Colombian Inca temples and palaces clearly reveals how exalted Machu Picchu was in its glory days.

Just before the Spanish conquest, Machu Picchu was mysteriously abandoned - and this was when it was still in its golden age. It subsequently lay buried under dense mountainous vegetation until 1911 when Yale explorer Hiram Bingham discovered it and began the reclamation process.

Archaeologists disagree on whether Machu Picchu was primarily a citadel, religious site or royal retreat. For decades the prevailing beliefs have been that it was principally either an Inca military stronghold or a religious center - or a combination of both.

Although there is scant evidence that Machu Picchu was an important sacred site, the stronghold theory bears weight because the builders chose an enviable defensive setting bordered on three sides by precipitous river canyon walls. Moreover, the inhabitants could survive a long siege. They were self-sufficient regarding food because they farmed and ranched the verdant Machu Picchu terraces.

Still, the citadel theory has a weakness. Would there be sufficient military value to justify constructing a major citadel in Machu Picchu's remote location?

Recently two archaeologists threw a monkey wrench into the stronghold vs. sacred site dispute. Their research suggests that Machu Picchu was built mainly as a spectacular summer mountain palace. If so, the designers knew what they were doing.

The best months for visiting are May to September. May is the prettiest month (the dense, subtropical mountain forests are exceptionally green) while August is the best all around month. The least desirable period is from October to April, the rainy season.

Most travelers take a day trip to Machu Picchu (they take the mid afternoon train back to their hotels in Cuzco). This leaves just about two hours at the site - and part of that precious time is expended by having lunch at the hotel. You'll have more hours to enjoy and explore the ruins if you stay overnight at the hotel at the site. You will be able to explore this travel wonder in the late afternoon and early the next morning when the tourist count is low. Rooms are scarce, so book well ahead.

The huge granite stone building blocks were hewn so precisely that they fit tightly together by themselves. No mortar or other adhesive was used. You cannot even insert a thin blade between their joints.

You can climb Huayna Picchu, the sharp peak immediately behind the ruins. The reward is a spectacular view of Machu Picchu below you. However, be fit and sure footed as the ancient stone steps to the top are steep and primitive. If you do climb the peak, avoid inclement weather as the stones could be slippery. And, in 2004, a visitor was struck by lightning when he reached the summit.

The conquering Spanish did not know of Machu Picchu because its existence was known only by local insiders.