Waikiki has its charms, but sometimes you want sand without a crowd. Across the Hawaiian islands there are quieter stretches of coast that reward a bit of effort — a steep trail, a lava-field hike, even a swim — with near-empty beaches. Here's where to look.

On Kauai's north shore, Kauapea Beach — literally nicknamed Secret Beach — requires a steep hike and offers no facilities, but you get sweeping views of Kilauea Lighthouse and plenty of space. Watch the water, though: swimming turns dangerous when seas are rough. Nearby, Pali Ke Kua (Hideaway Beach) hides at the bottom of a narrow path past a condo block and is one of the island's best snorkelling spots — go in summer when the water is calm and visibility is good.

Kauai's most extreme option is Honopu Beach, a stretch of sand beneath volcanic cliffs and the Honopu Arch. No trails reach it and boats can't land, so the only way in is a coastal swim from neighbouring Kalalau Beach. Fit swimmers get one of the most secluded spots in the state.

On Oahu, Halona Beach Cove is a tiny pocket of sand made famous by the 1953 film From Here to Eternity. It's a spot for confident swimmers and rock divers, with sea caves to explore — plus the Halona Blowhole next door, which can blast water 30 feet into the air when the surf hits right.

The Big Island's Makalawena Beach sits a 20-minute walk across a lava field in Kekaha Kai State Park. The payoff is pristine white sand, palm shade and good snorkelling off the lava outcrops.

Maui's Kaihalulu is Hawaii's only red-sand beach, its rust-coloured sand framed by lava cliffs and forested bluffs. Fair warning: the access trail has been badly eroded by landslides, so it's only for steady-footed hikers — and photographers who make it will be rewarded.

Lanai's Shipwreck Beach runs eight miles along Kaiolohia Bay, reached by an unmarked dirt road half an hour north of Lānaʻi City. The centrepiece is the rusting hull of a 1940s oil tanker stranded on the reef. Currents are strong, so it's a beachcombing and photography spot rather than a swimming one.

Finally, Molokai's Papohaku Beach — also called Three Mile Beach — ranks among the longest white-sand beaches in Hawaii, and the island's low tourist numbers keep it wonderfully quiet. It has solid camping facilities, and at certain times of day the sand glows orange in the light.

The common thread: the harder a beach is to reach, the emptier it stays. Pack good shoes, check ocean conditions before you set out, and pick the level of adventure that suits you — from a lava-field stroll to an open-water swim.