Only a stone's throw from Bali is Lombok. It's the next island in the eastern Nusa Tenggara chain, and it has the advantage of being less developed while still being able to offer a decent infrastructure for visitors to get around.
"It's not just for backpackers anymore," notes Kidder. "There's still some remoteness to it, but now there are luxury hotels as well." That means that if you're not up for more rustic Indonesian traditions like the mandi - where you shower by scooping bowlfuls of cool water over yourself - you can check in at a place like the Oberoi Lombok, where prices can stretch to almost $1,000 a night for the opulent Royal Villa Ocean View.
Most visitors to Lombok congregate around the Senggigi area, a coastal sweep north of the biggest city, Mataram. The white-sand beaches, the Rinjani volcano (Indonesia's third largest), and the indigenous Sasak culture - perhaps best known for its elegantly designed home furnishings - are all natural lures. An added bonus is the island's relatively small size (it's slightly more than 40 miles across), which allows you to experience much of what the island has to offer without having to spend most of your vacation worrying about getting from point A to point B.
Air service to Mataram and regular ferries from Bali bring Lombok within easy reach. But to take things an extra step, check out the Gilis, three tiny islands off Lombok's northwest coast. The stretches of white sand and plentiful coral reefs make Gili Air, Gili Meno, and Gili Trawangan dream spots for snorkelers and scuba divers, and the islands' beachside bungalows can make for a gorgeous but affordable getaway.
This spindly-looking island with peninsulas seemingly spinning off in every direction is almost the opposite of compact Lombok. But the island's far-flung arms have just as much richness to offer, both above and below the sea.
Formerly known as Celebes, Sulawesi is the world's 11th-largest island, spanning more than 100,000 square miles. Regular air service from Denpasar and Jakarta (courtesy of Indonesian airlines like Garuda) will get you to the capital, Ujung Pandang, or to Manado, at the island's northern tip, where the Bunaken Marine Park is said to house one of the most biodiverse coral-reef systems in the world, making the area a perennial favorite of scuba divers.
For a cultural experience like no other, there's the Tana Toraja area - the so-called Land of the Heavenly Kings. These mountainous highlands north of Sulawesi's capital are home to villages with traditional tongkonan houses, which are elevated and have dramatically curved roofs. Toraja's local hub is the town of Rantepao, where upgrades to roads and to hotels in recent years have made it more accessible to visitors.
The truly unique cultural attraction, though, is the area's funeral rites, which are among the most elaborate in the world, with festivities of feasting and dancing that can last more than a week. Ancestors are honored, too, with effigies placed in man-made caves that have been carved into sheer rock faces - these Toraja tombs have long fascinated anthropologists. In short, says Kidder, Sulawesi is perfect for one particular type of traveler: the culture fiend.