A trip to most museums lasts no longer than, what, two hours? But a visit to the Denver Museum of Nature & Science can be an all-day affair, thanks to increasingly intriguing programming and its IMAX theater. Since the museum is an educational institution, the films aren't always the standard action/adventures that do so well on the big screen. The Phipps IMAX Theater tends to show documentaries that dive into the inner workings of our planet, focusing on everything from oceans to dogs, and tickets are about half the price of those for an IMAX show elsewhere. Blowing your kid's mind for under $10? Worth every penny.