Yes, the Big Island is big, and yes, there's a lot to see. If you're short on time, consider flying into one airport and out of the other. That will give you the opportunity to see both sides of the island without ever having to backtrack. Decide what sort of note you'd rather end on to determine your route—if you'd prefer to spend your last few days near the beach, go from east to west; if hiking through rain forests and showering in waterfalls sounds like a better way to wrap up the trip, move from west to east. If you're short on time, head straight for Hawaii Volcanoes National Park and briefly visit Hilo before traveling the Hamakua Coast route and making your new base in Kailua-Kona.

From exploring the shores of green- and black-sand beaches to stargazing atop Mauna Kea, there's no shortage of ways to spend the day immersed in nature on the Big Island. Choose a couple or several of our favorite one-day itineraries to suit your interest and length of stay.

Green Hawaii

Take full advantage of Hawaii's living classroom. Visit one of the island's botanical gardens or take a farm tour in the morning, then head to the Natural Energy Lab, near the Kona International Airport, for a peek at how various enterprises raise shellfish, spirulina, and even seahorses. Wrap it up with an evening spent enjoying the delicious island-grown products at one of Waimea's top restaurants, such as local favorite Merriman's or its nearby neighbor Red Water Cafe.

Black and Green Sand

Check out some of the unusual beaches you'll find only on the Big Island. Start with a hike into Green Sands Beach near South Point and plan to spend some time sitting on the beach, dipping into the bay's turquoise waters, and marveling at the surreal beauty of this spot.

When you've had your fill, hop back in the car and head south about half an hour to Punaluu Black Sand Beach, the favorite nesting place of the endangered Hawaiian hawksbill turtle. Although the surf is often too rough to go swimming with green sea turtles, there are typically at least two or three napping on the beach at any given time.

Sun and Stars

Spend the day lounging on a Kohala Coast beach (Hapuna, Kaunaoa—also known as Mauna Kea—or Kua Bay), but throw jackets and boots in the car because you'll be catching the sunset from Mauna Kea's summit. Bundle up and stick around after darkness falls for some of the world's best stargazing.

For the safest, most comfortable experience, book a summit tour or stop in at the Onizuka Center for International Astronomy, a visitor center located at about 9,000 feet, or join the free summit tour at 1 pm on Saturday or Sunday, and return to the center to use the telescopes for evening stargazing.

Hike Volcanoes

Devote a full day (at least) to exploring Hawaii Volcanoes National Park. Head out on the Kilauea Iki trail—a 4-mile loop near Thurston Lava Tube—by late morning. Leave the park to grab lunch at nearby restaurants in Volcano Village just a few minutes away, or plan ahead and pack your own picnic before you start your morning hike. Later you can take a stroll past the steam vents and sulfur banks, and then hit the Jaggar Museum, which offers great views of Halemaumau Crater’s glow at night.

Majestic Waterfalls and Kings' Valleys

Take a day to enjoy the splendors of the Hamakua Coast—any gorge you see on the road is an indication of a waterfall waiting to be explored. For a sure bet, head to beautiful Waipio Valley. Book a horseback, hiking, or four-wheel-drive tour, or walk on in yourself (just keep in mind that it's an arduous hike back up—a 25% grade for a little over a mile).

Once in the valley, take your first right to get to the black-sand beach. Take a moment to sit here—the ancient Hawaiians believed this was where souls crossed over to the afterlife. Whether you believe it or not, there's something unmistakably special about this place.

Waterfalls abound in the valley, depending on the amount of recent rainfall. Your best bet is to follow the river from the beach to the back of the valley, where a waterfall and its lovely pool await.

Underwater Day

Explore the colorful reefs populated with tropical fish off the Big Island's coast. We challenge you to stop thinking about the world beneath the waves when you're back on land. Our favorite spots include easily accessible Kahaluu Beach Park (off Alii Drive), Kealakekua Bay, and the Kapoho Tide Pools.

Early morning or late afternoon is the best time to see pods of Hawaiian spinner dolphins that rest in calm bays, but you're likely to encounter turtles any time of day, along with convict tangs, puffer fish, triggerfish, angelfish, spotted moray eels, trumpet fish, and hundreds of other brightly colored species.

Thermal Springs and Waterfalls

Due to its remote location, many visitors skip Puna. They don’t know what they're missing. Venture into this isolated area for a morning, and you'll be rewarded with lava-tube hikes (Kilauea Caverns of Fire), volcanically heated pools (Ahalanui Park), and tide pools brimming with colorful coral, fish, and the occasional turtle (Kapoho Tide Pools).

Head to Hilo in the afternoon to visit Rainbow Falls, located right in town, or Akaka Falls, just outside town. Stroll Banyan Drive and Queen Liliuokalani Gardens before dining at one of Hilo's great restaurants.

Pololu and Paniolo Country

North Kohala is a world away from the resorts of the coast. Visit the quaint artists' community of Hawi; then head to the end of the road at Pololu Valley for amazing views.

A steep ½-mile hike leads to a fantastic black-sand beach surrounded by beautiful, sheer, green cliffs. Back on the road, head up Highway 250 to Waimea and the rolling hills and pastures of paniolo country. Indulge in a memorable meal at one of the town’s fantastic restaurants.

Venture Off-Road

Book an ATV tour or take your four-wheel drive for a spin to check out some of the Big Island's isolated beaches. There are green beaches (in addition to the Green Sands Beach) waiting in the Kau region and ruggedly beautiful white beaches with perfect turquoise water along the Kohala Coast; deal with the tough, four-wheel-drive-only roads into these beaches and you're likely to be rewarded with a pristine tropical beach all to yourself.