"Denver Monoliths," the enormous abstract sculpture in front of the Denver Art Museum's outrageous Frederic C. Hamilton Building, looks like the Flintstones meeting the Jetsons. The primitive forms of Beverly Pepper's charcoal-gray concrete sculpture provide a mighty contrast to the futuristic zigzags of Daniel Libeskind's shimmering silver building. An interesting fact in Pepper's bio is her age: The international art-world hipster is in her eighties! That's yet another reason her piece is one of the best things to see in this otherwise Real World kind of town.