I thought I'd seen blow holes. Growing up near Mt Maunganui had exposed me to the mild explosions of Moturiki Island but nothing could prepare me for Mapu'a a Vaea (the Chief's Whistle) at Houma on Tongatapu.

After a long suck of ocean swell, the sea headbutts an undercut coral shelf riddled with cracks from centuries of pounding. The only way out is up and vertical geysers of seawater spurt skyward with a hiss and a roar. This happens not just in one particular place, but along about 5km of coast. Spurts of water and sea mist explode along the reef as if the island were being strafed by a huge machine gun.

The raw power of the blow holes, and the eerie feeling that you could be consumed by the next wave, makes Houma hard to leave. After an hour of watching this amazing show, I was still shouting "Oooh look! Here comes a big one. This is going to be a real doozy!" However, Tongatapu had other attractions. This self-drive road show had to hit the dirt.


The island of Tongatapu isn't always the destination of choice when you're visiting Tonga. Often it's a stopover on the way to the blue lagoons of Vava'u. Domestic air schedules clash with international flights in a way that sometimes leaves you with a day to kill. But having explored the island twice, I know there are some real scenic treasures, and they're all free to visit.

Take the Anahulu limestone caves, on the south-eastern coast of the island. They're not well sign-posted, so you'll need a map from the Tongan Visitors Bureau to find them. Clearly the caves were once an attraction that demanded an admission charge - there's a decaying ticket office near the entrance. These days, you'll have them all to yourself. No admission, no electric lighting, no souvenir sales.

Inside the caves, torch light reveals stalagmites, stalactites and concrete stairs from the cave's hey day. Small, fast squeaking things fly in and out - it takes a while to determine they're swallows, not bats. After groping around in the dark for an hour, it's refreshing to walk down to Anahulu Beach. The path passes through a colourful, unrestrained Tongan cemetery. Brightly coloured strips of cloth and banners flutter in the breeze; swathes of artificial flowers embroider the plots.

Another "don't miss" on the Tongatapu touring map is the flying fox (fruit bat) village of Kolovai in the north-western corner of the island. But you need to look hard or you'll miss them. Having driven slowly through Kolovai a couple of times, with not a leathery wing in sight, we asked a local where the bats were hanging out. "Just look in the big trees," was the advice.

The bats look like decorative light fittings - black inverted triangles, hanging from every branch of huge casuarina trees. During daylight they hang in the their tree, snoozing and arguing. At dusk they unfold their fabulous wings and follow the scent of hot-blooded fruit.

In the Kingdom of Tonga, flying foxes are considered sacred. The bats are the official property of the King, and only royalty are allowed to hunt them.

Near Kolovai is Tongatapu's surfing strip, Ha'atafu Beach. The coastline faces west-northwest, putting the prevailing east-southeast trade winds directly offshore.

It's one of the few surfing areas in the South Pacific to enjoy excellent surfing conditions year round. With white coral sand and a wide lagoon for all-tides snorkelling, Ha'atafu is a slice of tropical heaven. Simple, comfortable fales can be found along the water's edge.

Offshore to the east of Ha'atafu is the swanky Royal Sunset Island Resort, and this is where you'd want to stay if Tongatapu was your primary destination. I say this because our hotel in downtown Nuku'alofa had a cat infestation - at night we were serenaded by feral moggies fighting in the ceiling. When staying in Tonga, it's a good idea to shoot for the quality end of the accommodation spectrum.

The open road speed in Tonga is a sedate 65km/h. In the villages, the limit is 40km/h. You wouldn't want to go any faster because chickens, children, piggies and potholes require a vigilant eye. We had a brush with the local law when my husband failed to spot the subtle transition from open road to village. While Tongatapu may lack many forms of technology, state-of-the-art radar guns remind you this island paradise knows how to keep the roads safe.

The officer involved wasn't to be swayed, however he did give clear instructions on where to find the Magistrates Court - the fine had to be paid that day.

Between the speeding ticket and the Magistrate's Court, we had another more pleasurable brush with the Tongan justice system. Outside the island's prison we found a roadside stall groaning with tropical fruit and huge taro, produce cultivated in the prison grounds by the inmates.

On Tongatapu, the prison is unfenced. The main deterrent against escape is simply the likelihood of getting caught. Anyway, there's no real need to escape, because the inmates get frequent home breaks to help them maintain their connection to the community.

Back in Nuku'alofa town, where most car rental journeys begin and end, a great day finishes with a night at the Billfish Bar & Restaurant. East of the royal family's iconic seafront palace, at the port end of town opposite Queen Salote Wharf, the Billfish has a 1950s Ernest Hemingway-goes-fishing feel about it. It isn't exactly fine dining, but the menu fits with the time capsule decor. You can have your lobster mornayed, garlic buttered or plain grilled. The band plays Girl From Ipanema and Satin Doll.

You can drink the local brew and meet the local characters. The waitresses wear flowers in their hair, and so will you by the end of the night. You know you're deep in the heart of the Good Old South Pacific.