1. Red Rock Canyon National Conservation Area
Hop in a car and drive 17 miles west to Red Rock Canyon National Conservation Area, where you'll find 196,000 acres of stunning desert landscape and the sandstone peaks that draw rock climbers from all over.
What you can do there: Hike. There are more than 30 miles of trails for novice and expert hiking. Stop at the visitor center on your way in for a map and advice from staff on the best trail for you. For a real workout, you can bike a 13-mile loop through the park with an elevation change of 1,000 feet in the first 4.6 miles.
If you're short on time: Explore that 13-mile loop by car. One impressive sight is the Keystone Thrust Fault, caused by a fracture in the earth's crust that pushed the gray carbonate rocks of an ancient ocean over the newer layers of tan and red sandstone.
Wildlife: You might spot big horn sheep, gray foxes and burros, amid vegetation such as Joshua trees, yucca and black brush.
What you should know: Bring water (it is the desert, after all) and snacks. In a pinch you can buy water at the visitor center, but there's no available food or drink along the scenic drive.
2. Hoover Dam and Lake Mead
Hoover Dam, located about 45 minutes from the city, is an awe-inspiring engineering feat. This 6.6 million-ton concrete behemoth holds the mighty Colorado River at bay. And, thanks to the dam, we have Lake Mead. The Lake Mead National Recreation Area is a 1.5 million-acre national park (including 700 miles of lake shoreline) for kayaking, canoeing, and hiking.
What you can do at the dam: Try the hour-long guided tours of the power plant, including a look at the massive generators and pipes below the dam.
What you can do at and around Lake Mead: You can rent boats by the hour or day at the lake's Las Vegas Boat Harbor, or take a cruise on the Desert Princess. Hikers and bikers can check out the 3.7-mile Historic Railroad Tunnel Trail in Boulder City, built to haul supplies to the dam construction area. You'll wind your way through five tunnels and across spectacular scenes of the lake and desert.
Don't miss: At the dam, be sure to take a stroll along the sidewalk at the top for a great view and the chance to stand on the state border — with one foot in Nevada, the other in Arizona. Bring a picnic to the park, which has countless perfect scenic spots for lunch al fresco, many of them shaded (you can also grab a meal at the boat harbor).
What you should know: If hiking in the park, again, bring a lot of water: The National Park Service actually suggests two liters or more for long hikes. The air is dry and temperatures can skyrocket.
3. Valley of Fire State Park
About an hour (55 miles) northeast of Vegas and a popular spot for camping, this park regularly wows day-trippers with how over-the-top stunning the colorful sandstone formations are.
What you can do there: See 3,000-year-old petroglyphs from the Ancient Pueblo peoples (Anasazi). There are some easily viewed right at the Atlatl Rock picnic area, and others that you can reach via a gravelly quarter-mile path. The park also has 18 miles of roads: The scenic White Domes Road will take you past Rainbow Vista, an oft-photographed panorama of undulating rock layers in reds, whites, browns and golds.
Don't miss: Pass the Rainbow Vista at the end of the road, and try an easy-to-moderate 2-mile-long loop hike to White Domes (a group of round, creamy sandstone mounds) that will allow you to get up close to the striations of rock. About 100 feet of the trail is an almost tunnel-like slot canyon, where you can see every vein of color in the walls surrounding you (and get some welcome shade).
Wildlife: You may spot roadrunners, ravens, snakes, coyotes, black-tailed jackrabbits and desert big horn sheep.
What you should know: There's no restaurant, just a few snacks sold in the visitor center gift shop, so bring your own. And you won't be seeing many gas stations, so fill up before you leave the city.
And consider timing your visit for early in the morning. It's often 15 or 20 degrees cooler at sunrise than at sunset and the fiery glow on the red rocks is just as beautiful.