The Inca fortress the Spanish never found. This historic site was found in the early 1900's. What I found amazing was that after passing through the admissions area, I had complete access to everything. There are no fences, guard rails, gates, or hand rails on the steep steps. You should have a guide to explain particular sites within Machu Picchu, but you can just roam on you own with a guide book. One of the wonders of the world.
The Loire Valley, southeast of Paris, has chateaux illustrating the incredible wealth of nobles and royalty of centuries past. At the other end of the spectrum, the village of Oradour-sur-Glane is a monument to hundreds of common people whose lives ended one day in 1944.
The southern coast of France has great beaches and quaint little towns. Evidence of past Roman conquests is everywhere, but only adds to the charm. Monaco: a city covered in money. Deposit 10 million Euros and you can become a citizen. Favorite site: Pont du Gard. Favorite village: Saint Paul de Vence.