Henderson's location on the southeastern edge of the Las Vegas Valley puts it closer to some of the region's best day trips than the Strip is.
Valley of Fire State Park is the most dramatic of the lot — about an hour's drive northeast. Nevada's oldest and largest state park takes its name from the red Aztec sandstone that blazes across the landscape. Elephant Rock, Arch Rock, and the aptly named Fire Wave are among the formations; petroglyphs left by the Basketmaker people appear throughout. The visitor center is a good first stop. Entrance is $10 per vehicle; campsites are available if you want to stay.
Hoover Dam is 20 miles south on US-93 — about 30 minutes from Henderson. You can walk across the dam for free and look down 726 feet into Black Canyon; the free visitor center covers the basics. The paid tours (around $30–40) go inside the dam itself and are worth it. Don't miss the art deco details — the Bronze "Winged Figures of the Republic" at the Nevada intake towers are genuinely striking.
Lake Mead wraps around the dam and stretches east into Arizona. Swimming, kayaking, and boating are all popular. Boulder Beach, just north of the dam, is the most accessible spot.