Their topography instantly marks them out as good walking territory. Unlike the flat and mostly tiny Mamanuca Islands closer to Nadi, the Yasawas are ancient volcanoes, their rolling, grassy ridges broken by towers of ancient lava.
There's not a lot in the way of virgin bush, thanks to centuries of slash-and-burn agriculture, but the open tops guarantee clear views. Most resorts will have at least a trail to the nearest hilltop, and some offer guides for more demanding walks.
One thing to bear in mind in Fiji is that every bit of land is owned by someone. It's poor manners to march all over someone's ancestral land without permission, so always ask at the resort first.
Sometimes a guide is needed because the maze of pathways can be hard to follow; other times the guide is your passport to cross another village's land.
One of many views from the Barefoot Island Trail on Drawaqa Island. Photo / Peter de Graaf
The first walk I tackled was to the top of one of those implausibly steep lava towers. Called Ului Nakauka, it is one of a series of near-vertical peaks that follow the spine of Waya Island like a tuatara's spikes.
Once the day had cooled (hiking at noon in the tropics is not recommended) the staff at Octopus Resort rustled up a guide from a nearby village, a 26-year-old pig farmer named Sio.
Sio wasn't a big talker at first but he was good at pointing out the pig pens. As the track zig-zagged uphill we passed villagers planting cassava, a root crop, in freshly burnt clearings.
As the bush gave way to grassy ridges and the views over Waya's bays and headlands opened up, it turned out that Sio had an ulterior motive for being my guide. He had a girlfriend on the next island and had a romantic photo opportunity in mind, involving himself, his hands in a heart shape, and her island in the background.
I hadn't expected a village pig farmer to go hiking with a smartphone. Nor had I expected him to post romantic photos on his girl's Facebook page. Proof, if it was needed, of the almost universal reach of social media.
That broke the ice between us and sparked a comical series of selfies, most of which I have since deleted. A word of advice: If, like me, you are a sunburnt, sweating, European man of middle age, do not pose for a selfie with a handsome Fijian in his 20s who looks like he's been working out since he left kindergarten. It will not do your self-image any favours.
Soon we reached the base of the peak itself. What had been a straightforward walk suddenly became something entirely different. The way up was via a narrow cleft in the rock and using the technique of bracing your hands on either side of the gap and climbing up a series of tiny footholds someone had helpfully improved with concrete. I inched up fearfully. Sio scampered up casually in a pair of jandals.
Up top, we couldn't have been more than a few hundred metres above sea level but the view was extraordinary. Directly below was Sio's village, an orderly grid of iron and thatch roofs half hidden in coconut palms; behind us, a row of even more vertiginous peaks; and all around us the green fingers of Waya Island reaching into the sea, stretching and sparkling to the horizon.
If the way up was nerve-wracking, the way down was terrifying. A fierce wind tearing at our limbs didn't help. If it wasn't for Sio's calm guidance I'd still be up there now. Did I mention my fear of heights?
Farmer, online romantic and guide, Sio. Photo / Peter de Graaf
We made it down just as the sun was setting and villagers were hauling their boats in for the night. And just in time for the resort's nightly kava ceremony.
I was trusted to tackle the other walks on my own. It may have helped that they were on small islands where land ownership was simpler.
In the case of Drawaqa Island, about 45 minutes further north by ferry, the well-maintained Barefoot Island Trail climbed a series of hills offering sublime views of reefs, channels and surrounding islands.
Still further north, a rough trail from Tavewa Island's Coralview resort to a cellphone tower - the 21st century intruding again - offered fine sunset views of the island's bigger and more barren neighbour, Nacula.
But the best view of all was from a hilltop on Naviti Island, reached in an easy 90-minute stroll along an undulating, open ridge from Botaira Resort.
To the north, the island's crinkled spine stretched into the distance, dotted with trees that seemed transplanted from a Dr Seuss book; to the south a series of small, intensely green islands looked like stepping stones.
I'm not eccentric enough to urge anyone to forget the other pleasures of the Yasawas for the sake of a bit of hiking, because the greatest attractions are to be found underwater and in the warmth of their people.
But every now and then, try exploring the hills behind those white sandy beaches. There, too, is beauty.
Hiking
Most islands in the Yasawas offer some kind of hiking. On the smaller islands it might be a half-hour stroll to a hilltop; on bigger islands you can walk for hours over rough trails to vertigo-inducing peaks.
Check first whether you need permission from the land owners. A guide can be a good investment, with some of the longer trails now overgrown as motorboats replace walking as the islands' main means of transport. Avoid the hottest time of day, bring plenty of water, and wear closed shoes or boots on the rougher trails because cuts quickly turn septic in the tropics.
CHECKLIST
Getting there: The Yasawa Flyer catamaran calls in at most islands every day, leaving Nadi's Port Denarau at 8.30am and returning around 6pm.
Accommodation: Starts from about $23 a person per night for a dorm bed at Octopus Resort, with the compulsory three-meal package of $69 a day. A traditional bure for two at Botaira Resort, including meals, is $340 a couple per night, with discounted rate for longer stays.
The writer explored the Yasawas as a guest of Tourism Fiji, Awesome Adventures, and local resorts.
