Machu Picchu
Machu Picchu remains the most famous Inca site in the world, and the clearest conditions tend to fall between late April and early October, when mountain mist is less likely to roll in. That said, weather rarely diminishes the impact of arriving at the citadel for the first time. Built in the fifteenth century and brought to international attention in 1911, it has lost none of its power to stop visitors in their tracks.