Waterfalls: Rushing waterfalls thundering downward into sparkling freshwater pools are some of Hawaii's most beautiful natural wonders. Kauai is loaded with waterfalls, especially along the North Shore and in the Wailua area, where you'll find 40-foot Opaekaa Falls, probably the best-looking drive-up waterfall on Kauai. With scenic mountain peaks in the background and a restored Hawaiian village on the nearby riverbank, the Opaekaa Falls are what the tourist bureau folks call an eye-popping photo op.

Gardens: The islands are redolent with the sweet scent of flowers. For a glimpse of the full breadth and beauty of Hawaii's spectacular range of tropical flora, we suggest spending an afternoon at a lush garden. Na Aina Kai Botanical Gardens, on some 240 acres sprinkled with about 70 life-size (some larger than life-size) whimsical bronze statues, lies hidden off the beaten path of the North Shore. Other great gardens are Allerton Garden in Poipu and Limahuli outside of Hanalei.

National Wildlife Refuges: Kauai has three wildlife refuges: Kilauea Point, which protects seabirds; Huleia, which shelters Hawaiian endemic birds and wetlands; and Hanalei, which maintains a sheltered area for Hawaiian birds and the watershed.

The Grand Canyon of the Pacific -- Waimea Canyon: This valley, known for its reddish lava beds, reminds everyone who sees it of Arizona's Grand Canyon. Kauai's version is bursting with ever-changing color, just like its namesake, but it's smaller -- only a mile wide, 3,567 feet deep, and 12 miles long. All this grandeur was caused by a massive earthquake that sent existing streams flowing into a single river, which then carved this picturesque canyon. You can stop by the road to view the canyon, hike down into it, or swoop through it by helicopter.