Creeping Up to the Ooze. Hawaii Volcanoes National Park is a work in progress, thanks to Kilauea Volcano, which pours red-hot lava into the sea and adds land to the already-big Big Island every day. Since the ongoing eruption began in 1983, Kilauea's been bubbling and oozing in a mild-mannered way that lets you walk right up to the creeping lava flow for an up-close-and-personal encounter.

Going Underwater at Kealakekua Bay. The islands have lots of extraordinary snorkel and dive sites, but none are so easily accessible or have as much to offer as mile-wide Kealakekua Bay, an uncrowded marine preserve on the South Kona Coast. Here, you can swim with dolphins, sea turtles, octopi, and every species of tropical fish that calls Hawaii's waters home.

Discovering Old Hawaii at Puuhonua O Honaunau National Historical Park. Protected by a huge rock wall, this sacred Honaunau site was once a refuge for ancient Hawaiian warriors. Today, you can walk the consecrated grounds and glimpse a former way of life in a partially restored 16th-century village, complete with thatched huts, canoes, forbidding idols, and a temple that holds the bones of 23 Hawaiian chiefs.

Stargazing from Mauna Kea. A jacket, beach mat, and binoculars are all you need to see every star and planet in this ultra-clean atmosphere, where the visibility is so keen that 11 nations have set up telescopes (2 of them the biggest in the world) to probe deep space.

Watching for Whales. Humpback whales pass through waters off the Kona Coast every December through April. To spot them from shore, head down to the Keahole National Energy Lab, just south of the Kona airport, and keep your eyes peeled as you walk the shoreline. To get here, follow Queen Kaahumanu Highway (Hwy. 19) toward the Keahole airport; 6 miles outside of town, look for the sign NATURAL ENERGY LAB, and turn left. Just after the road takes a sharp turn to the right, there's a small paved parking area with restrooms; a beach trail is on the ocean side of the lot.

Savoring a Cup of Kona Coffee. It's just one of those things you have to do while you're on the Big Island. For a truly authentic cup of java, head upcountry to Holuakoa Cafe, on Mamalahoa Highway (Hwy. 180) in Holualoa (tel. 808/322-2233), where owner Meggi Worbach buys green coffee beans from local farmers, roasts and grinds them, and pours you the freshest cup of coffee you've ever had.

Hanging Out in Waipio Valley. Pack a picnic and head for this gorgeously lush valley that time forgot. Delve deep into the jungle on foot, comb the black-sand beach, or just laze the day away by a babbling stream, the tail end of a 1,000-foot waterfall.

Chasing Rainbows at Akaka Falls. When the light is right, a perfect prism is formed and a rainbow leaps out of this spectacular 442-foot waterfall, about 11 miles north of Hilo. Take time to roam through the surrounding rain forest, where you're sure to have close encounters with exotic birds, aromatic plumeria trees, and shocking red-torch ginger.

Gawking at the Day's Catch in Honokohau Harbor. Every afternoon between 4 and 5pm, local fishermen pull into the fuel dock to weigh in their big-game fish. And when we say big, we mean it: We're talking 1,000-pound blue marlins and 150-pound yellowfin tunas, plus plenty of scale-tipping mahimahi, ono (also known as wahoo), and others. Sit in the bleachers and check out these magnificent creatures. Afterward, you can walk the docks, inspect the boats, and chat with captains and crew.

Hunting for Petroglyphs. Archaeologists still aren't sure who's responsible for these ancient rock carvings, but the majority of Hawaii's are found in the 233-acre Puako Petroglyph Archaeological District, near Mauna Lani Resort. The best time to go looking for canoes, turtles, dancers, and family groups is in the cool early morning or late afternoon. There are more than 3,000 petroglyphs in this area alone -- see how many you can spot!

Shopping at the Hilo Farmers Market. For less than $10, you can buy a pound of rambutan (a sweet Indonesian fruit), a bouquet of tropical orchids, and a couple of tasty foot-long Hawaiian laulaus (pork, chicken, or fish steamed in ti leaves). But be sure to arrive early -- the market opens at sunrise -- because many of the 60 or so vendors quickly sell out.