If you’re scoping out the Grand Canyon or visiting Las Vegas, you may be considering a daytrip to the Hoover Dam – the National Historic Landmark that keeps the Colorado River at bay. At the time of its completion, dam workers used 6.6 million tons of concrete, more than 5 million barrels of cement and 45 million pounds of steel. And that’s not all you need to know about the Hoover Dam:

Who built the Hoover Dam? President Calvin Coolidge authorized the Hoover Dam (then known as the “Boulder Canyon Project”) in 1928. A consortium of construction firms, called Six Companies, won the contract in 1931. Laborers toiled for around four years, completing the engineering marvel in 1935.

What is the purpose of the Hoover Dam? The Hoover Dam holds water in Lake Mead where it is stored so it can be diverted strategically to irrigate local fields.

Why was the Hoover Dam built? The Hoover Dam was built to divert water from the Colorado River to various corners of the then-developing southwestern United States.

Tours of the facility are available on-site and include access to the power plant and the dam’s passageways. However, independent tour companies – many of which depart from Las Vegas – also make stops at the dam. Many of these organized tours include additional experiences, such as a cruise on Lake Mead or a mountain bike ride from Boulder City, Nevada. Considering both traveler sentiment and expert input, U.S. News gathered seven of the best Hoover Dam tours available.

Comedy on Deck Tours – Hoot & Hoover Dam

Guides double as stand-up comedians on this approximately seven-hour tour of the Hoover Dam. In addition to transportation and a dedicated driver, you’ll have the opportunity to walk across the top of the dam, see interior generators and learn how they work, and enjoy a made-to-order lunch. Tourists call it a great way to spend a day and the best “dam” tour around thanks to the entertaining and talented guides. This tour departs at 8 a.m. on Mondays, Wednesdays and Fridays and costs approximately $100 per person. The company also offers Hoover Dam tours that stop at the Clark County Museum, along with several Grand Canyon tours, each of which offer a comedic take.

Awesome Adventures – Hoover Dam Mountain Bike Tour

For a heart-pumping tour of the Hoover Dam, consider this cycling excursion from Awesome Adventures. You’ll ride a mountain bike on an easy, downhill trail from Boulder City, cycling past Lake Mead before stopping at the Hoover Dam for 90 minutes. Along the 13-mile trip, you’ll stop to admire the scenery (including herds of bighorn sheep) and enjoy a snack and water break. Las Vegas Strip hotel pickups begin at 8 a.m.; expect to be dropped off at your hotel around 3:30 p.m. Patrons rave about the guides and the company. Tickets start at $179 per person and participants must be 14 years or older. Awesome Adventures also offers air, land and water tours in Nevada, the Grand Canyon area and Utah.

Papillon – Hoover Dam Heli Tour

Marvel at the Hoover Dam from a bird’s-eye view with this helicopter tour from Papillon. You’ll soar 2,500 feet above the dam, the Colorado River and Lake Mead on the six-minute, 10-mile flight. Along the way, you’ll be entertained by headset narration detailing the history of the area. Travelers enjoy the flight, saying the views are spectacular. You can book daily every 15 minutes from 9:15 a.m. to 4 p.m. Tickets start at $69 for all ages. Papillon also offers longer tours of Las Vegas, the Grand Canyon and Antelope Canyon, among other locations.

Gray Line Las Vegas – Hoover Dam and Lake Mead Cruise Tour on the Desert Princess

Following a tour of the Hoover Dam, you’ll hop on a paddle-wheeler boat for a relaxing cruise around Lake Mead. During the 90-minute cruise, you’ll enjoy a deli-style lunch on board the boat. On your way back to Vegas, you’ll have the chance to take pictures with the iconic “Welcome to Fabulous Las Vegas” sign. Participants say the nearly eight-hour tour is a relaxing outing, but others complain there is not enough time to properly tour the Hoover Dam. Tours depart at 10 a.m. on Mondays, Wednesdays, Saturdays and select Fridays. Tickets start at $129 and include lunch and hotel pickup. Gray Line offers other tours to see the Hoover Dam, Grand Canyon and other nearby sights.

Big Horn Tours – Hoover Dam Hummer Tour

If you’re on the hunt for a half-day, small-group tour of the Hoover Dam, this four-hour excursion from Big Horn Tours may be just what you’re looking for. After getting picked up from your Las Vegas hotel, you’ll visit the Hoover Dam visitor center and see its exhibitions, tour the dam power plant, and step out on to the observation deck for unparalleled views. Reviewers say the tour is fun and that the guides are informative. Tours – which are restricted to six participants – run daily with pickups at 7:40 a.m. or noon and tickets start at $96 per person. Big Horn also offers tours of the Grand Canyon and Death Valley National Park.

Vegas Trike Adventures – Hoover Dam Trike Tour

Explore the area surrounding the Hoover Dam behind the wheel of your very own Rewaco trike, a three-wheeled motorcycle. During the 3 1/2-hour trip, you’ll take in spectacular views of Lake Mead, the Hoover Dam, Boulder City and more. Two tour guides accompany your group, pointing out landmarks and stopping for pictures along the way. Travelers call this journey an amazing experience, though some wish they had a bit more time to explore the dam. Tours start at 9 a.m. Monday through Saturday and conclude around 2:30 p.m. Tickets cost approximately $180 per two-person trike with a combined passenger weight of 400 pounds. Complimentary shuttle service from Las Vegas to Boulder City is included. No motorcycle license is needed. Vegas Trike Adventures also offers tours of the Las Vegas Strip and provides trike rentals.

Pink Adventure Tours – Hoover Dam Tour

Take in views of Lake Mead, the Hoov
er Dam and the Colorado River on this four-hour tour, which is capped at 10 participants. After departing from Las Vegas, the tour stops in the Hoover Dam visitor center, where presentations and exhibitions detail the history of the dam’s construction. From there, your guide will take you to the Arizona side of the dam where you’ll get a chance to stroll along this architectural marvel. Take your pick between a morning or afternoon departure. Tour prices start at $99 for adults and $90 for children ages 3 to 12; this journey isn’t suitable for kids younger than 3. Most reviewers give this tour high marks, praising the knowledgeable, entertaining tour guides and comfortable vehicles. Pink Jeep Tours also offers Jeep adventure tours in Sedona, Arizona, the Grand Canyon and Great Smoky Mountains National Park.