The Mapu'a 'a Vaea Blowholes

Along the rugged south coast of Tongatapu, the main island, lies one of Tonga's most spectacular natural sights, the Mapu'a 'a Vaea, or Chief's Whistles, blowholes. Here, for several kilometres, the flat coastal terrace of ancient coral rock is riddled with countless holes, and as the powerful Pacific swells surge against the shore, they force jets of seawater exploding upward through them, sometimes reaching 30 metres high. On a day of good swell, hundreds of these spouts erupt and hiss along the coast at once, whistling and thundering in a dramatic, mesmerising display of the ocean's raw power against the land.

What you actually see

• The blowholes - the jets of seawater exploding through the rock.
• The coastal spectacle - the hundreds of spouts along the shore.
• The rugged coast - the wild south coast of Tongatapu.
• The sound - the whistling and thundering of the spouts.

When to go

May to October, the season of stronger swells and trade winds, tends to produce the most dramatic blowhole activity, though a good day depends on the ocean swell rather than the calendar; the spectacle is best when the sea is up and the swells are large. The blowholes are an easy drive from the capital along the south coast.

Honest expectations

The blowholes' drama depends entirely on the ocean swell, so on a calm day they can be modest, while on a day of big swell they are spectacular; the rocky coast is for viewing rather than swimming, and care is needed near the slippery, powerful blowholes. As a dramatic, easily reached natural spectacle when the swell is up, though, one of the most extensive blowhole coasts in the Pacific, the Mapu'a 'a Vaea are a memorable sight on Tongatapu.

Nearby

The capital Nuku'alofa and the ancient sites of Tongatapu are within reach.