Learn about the history of this wonder of technology through either a one-hour guided tour ($30) or half-hour power plant tour ($11). Open from 9 am- 6 pm daily; last ticket sold at 5:15 pm. Parking fee: $7. www.usbr.gov/lc/hooverdam. 30 miles southwest of Las Vegas. Take U.S. Highway 93 to Nevada State Route 172. 702.494.2546.