In 1996, I attended some training at the Albright Training Center in Grand Canyon National Park. On one of our weekends, some friends and I drove up to northeast Arizona to visit Navajo National Monument. Keet Seel is one of the most interesting ancient ruins I've ever visited, located in the middle of the Navajo Nation and accessible only by a seven-mile hike one-way, and then only with a park service guide. The tradeoff is that the ruins are some of the best preserved anywhere. The architecture and colors are absolutely stunning.