In the tale of King Arthur's round table, Sir Lancelot, like many of the other knights, set off to find the Holy Grail and spent many years questing in strange places for this sacred relic. A couple of whimsical Spanish writers adapted this legend and suggest that Lancelot came across an island in the ancient Atlantic mists, took to it, and was never seen again at Camelot. He named it after himself - in Spanish, Lanzarote.

It's a good story, and the reality of the place might have appealed to the handsome knight, maybe a bit jaded after his amorous jousting with Queen Guinevere, who fancied the iron pants off him - it might even have reminded him of his mythical home. In the island's cooler north, when the stiff north-easter blows, streams of cloud whip across mountain tops, pour down into the extinct volcanoes and, magically, seem to vanish. In the hotter south, despite the absence of dragons, he would have found fire-belching volcanoes. Their eruptions 270 years ago give this easternmost of the Canaries its astonishing character.

The tortoise-shaped island is covered in rock blasted into myriad shapes, forms, textures and colours, from mountains to deserts to 500m sea cliffs, 110km off the coast of Morocco. It looks like a cross between Death Valley and the surface of the moon. From the magnificent fire mountains in the Timanfaya national park to the sandy desert that surrounds the surfers' beach at Famara, to the malpais (badlands) you find all over, this could be God's rock junkyard.

Modern-day travellers seeking nothing more exotic than to get away from it all and enjoy the year-round 20C-plus temperatures, should start with a visit to Timanfaya, the area where the biggest eruptions took place between 1730-36. Even now, the ecology is still developing, so travel in the park is controlled to prevent damage to processes being studied by vulcanologists, zoologists, botanists and geologists. There are organised walks once or twice weekly but they must be booked in advance, otherwise you cannot wander about on your own. You can take a coach tour or join a camel train for a jolting 20-minute amble along the steep side of a volcano.

If you go on to the tourist centre at Islote de Hilario, the restaurant El Diablo serves up hot meals cooked using geothermal energy. And you can enjoy your very own geyser: on the hilltop outside the building are metal-lined vents leading down to hot rocks at 400C six metres below the surface crust. On request, one of the park attendants will hurl a bucket of water into a vent, and no more than 20 seconds later, with a tremendous roar, it explodes back out as steam, jetting metres into the air.

Elsewhere, the landscape is dotted with small villages and towns, such as Teguise, or Yaiza, or Haria with its thousands of palm trees, all of which retain their traditional two-storied, wooden-shuttered charm. They are all painted white with green or blue detailing. This colour control and the absence of modern buildings away from the coast is the result of a policy that corrals the popular holiday trade and its massive building development mainly along the south-east, from Costa Teguise through Puerta del Carmen and down to Playa Blanca.

The latter is the Lanzarote of the package tour, with miles of big hotels and apartments, bars and cafes, beaches and parasols. You could spend a day on the beach parascending, jetskiing or just broiling, go to an Irish pub for fish and chips, then hit a nightclub before collapsing in your aparthotel or timeshare apartment. And there are some very nice beaches, particularly at the eastern end of Costa Teguise, where the white sand and clear water of Playa del Jablillo make it ideal both for children and snorkellers.

Probably the best beach for general swimming, boogie-boarding and going butt-naked is Playa de Papagayo, situated on the southern tip, a teeth-jarring 6km drive over dirt roads. Because it's part of a nature reserve, there is a 3 euros (£1.80) entrance fee.

The Faustian pact on tourism was dreamt up by the island's favourite son, César Manrique, once an internationally renowned artist, who in the late 1960s foresaw the mass travel boom and wanted to protect Lanzarote's environment. Manrique created several centres to demonstrate his ideas. Probably the most famous is the Jameos Del Agua, on the north-east coast, where he transformed underground volcanic chambers - giant bubbles - into a concert hall, restaurant, and night-club around a central pool where there are rare, tiny, white, blind crabs. It's a remarkable place, spoilt by the electronic music.

Manrique was killed in a car crash in 1992. His house, now a museum and gallery, is plumb in the middle of a lava field. When you stand in one of the cool white rooms with his powerful abstract paintings blazing on the walls and gaze out at the lava shapes that surround you, like giant creased and folded sheets of solid treacle, you can take comfort in the thought that there is little chance of Lanzarote's volcanoes erupting. The last one did so in 1824; most are extinct.

In truth, Lanzarote got its name from the 14th-century Genovese navigator, Lanceloto Malocello. The island's historical origins may lack the romantic associations of Camelot, but maybe getting his name carved in history was Malocello's grail.

Way to go

Getting there:
Simply Spain (020-8541 2200, simplytravel.co.uk) offers seven nights' self-catering at Villa Casa El Quinto from £500pp (two sharing) including flights and car hire. For departures next Thursday, self-catering offers range from £99pp for seven nights including flights (Cosmos, 0870 9010790) to £511 (Sovereign four-star, 0870 5768373). Cosmos offers four-star hotel half-board for £379 or all-inclusive for £459. Flights only start at £69 (First Choice, 01293 560777, and Unijet, 0870 5336336). Independently booked accommodation can be found from around £140 (1-2 bed apartment) up to £600 (private villa with pool etc).

Getting around:
Hertz (0870 5996699, hertz.co.uk) offers one-week's car hire from Arrecife airport from £130.

Best beaches:
North: Caletones Blancos near Orzola, good for kids; Playa del Risco, for strong walkers. South-east: Playa del Jablillo at Costa Teguise; Playa Grande and Playa Fariones at Puerto del Carmen; Playa de Papagayo. The island of La Graciosa, 30 mins by ferry from Orzola, about £8 return.

Where to eat:
Seafood is good and reasonably cheap at places such as Os Gallegos and El Norte in Orzola, Casa Miguel in Arrieta, Costa Azul and Torano in El Golfo. Ikarus in Teguise is upmarket and offers modern European.

Recommended reading:
Landscapes Of Lanzarote by Noel Rochford (Sunflower £9.99).

Further information:
The Spanish Tourist Office (020-7486 8077, tourspain.co.uk, tourspain.es).

Area code: 00 34 928.
Flight time Gatwick-Arrecife: 4hrs.
Time difference: +1hr.
£1 = 1.51 euros.