Las Vegas Exploring

Best Underwater Adventure: Silverton Casino's (3333 Blue Diamond Rd.; 866/946-4373) aquarium may inspire you to buy a snorkel mask and head for Lake Mead with the money you saved by seeing these fish for free. A variety of fresh and saltwater exhibits display underwater scenery from around the globe. There are also shows, including animal feedings and an underwater mermaid dance, throughout the day.

Best Place to Marvel at the Power of Physics: Movies, books, and television can only begin to describe the atom bomb's story. You can stand where some of the most infamous photographs of the 20th century were taken by touring The Atomic Testing Museum, a nuclear test site with the U.S. Department of Energy (755 E Flamingo Rd.; tel. 702/295-0944). Tours are free and offered monthly, but be advised that security precautions must be taken more than a month ahead of time; contact the number above for more information.

Best Place to Determine the Unknown: Some 150 miles outside of town, the world's most sophisticated secrets are taking flight at Area 51. Though this isn't designed to be a tourist attraction, you can still take an excursion to the site with a durable vehicle, water, and a good deal of respect for the boundaries of the Air Force base. Click on this link for a full explanation of how to visit.

Best Place to Respect the Greatest Generation: Hoover Dam is a true marvel that dwarves any of the Strip's latest engineering feats. The fact is that Las Vegas, as well as most of the Southwest, owes its existence to America's largest reservoir and the hard work of Americans who saw our nation through the Great Depression. Visiting the dam without spending much is a bit tricky. Here's how to do it: Park on the Arizona side to avoid fees and try to resist the tour or gift shop. Two cost-effective exhibits that will satisfactorily inform you about the massive project are at Lake Mead's Alan Bible Visitor Center (tel. 702/293-8990) and the Boulder City Museum of Hoover Dam (1305 Arizona St., Boulder City; tel. 702/294-1988).

Best Place to Learn: Can you describe how Sin City was originally settled? Here's a hint: An old-western society existed along Las Vegas Creek for almost a century before Bugsy Siegel walked into the Flamingo. For the cost of a slot pull ($3), Old Las Vegas Mormon Fort State Historic Park (500 E. Washington Ave.; tel. 702/486-3511) will fill you in on all you need to know to win a wager.