The stones in the most handsome buildings throughout the Inca Empire used no mortar. These stones were cut so precisely and wedged so closely together that a credit card cannot be inserted between them. Aside from the obvious aesthetic benefits of this building style, there are engineering advantages.
Appreciating Machu Picchu for its aesthetic qualities is no slight to its significance. The Incas obviously chose the site for the immense power of its natural beauty. They, like us, must have been in awe of the snowcapped peaks to the east, the rugged panorama of towering, forested mountains and the sacred cliff of Putukusi to the west, and the city sitting gracefully like a proud saddle between two huge cerros, or peaks. It remains one of the most thrilling sights in the world.