In Arizona, the mighty Colorado river pumps like an artery through the heart of the Grand Canyon. With 161 rapids, those who have run the river say it&rsquos the trip of a lifetime it&rsquos no wonder the waiting list for independent whitewater trips extends for years. If you have the time and money, best to hire a private guide service (www.oars.com/grandcanyon). But you don&rsquot have to take out a life-insurance policy to check out the sublime canyon views. Just head for the deck of El Tovar Hotel on the South Rim, located within the Grand Canyon National Park (www.nps.gov/grca). Founded in 1909, the park is great for camping and hiking,offering a geological wonderland to explore. On the neighbouring Hualapai Indian Reservation,the Grand Canyon Skywalk (www.grandcanyonskywalk.com), a $31 million, glass-bottomed bridge that extends over the canyon, opened in 2007.