'It never rains in Santorini during the summer," said Dionisis. "It precipitates." I watched the sudden downpour of precipitation splashing relentlessly on to my plate of Greek salad and looked at him doubtfully. "We get the wind," he admitted, deftly re-anchoring a tablecloth that looked set to take flight. "On account of being so high up. But never rain." Plop, plop, plop went the steady sound of ever more raindrops into my beaker of wine. Dionisis shrugged. "Special place, special climate," he said.
He might not win any prizes as a weatherman, but Dionisis was certainly right about Santorini being special. The southernmost of Greece's Cycladean islands, formed in its current incarnation from a series of cataclysmic volcanic explosions, it is one of the loveliest and most awesome Mediterranean settings I've come across. I'd fallen under its spell before the plane had even landed.
Santorini is an astonishing sight from the air – a collection of five islands floating on the blue of the Aegean Sea like an incomplete jigsaw puzzle. Once they were a single landmass – a walnut-shaped island known as Strongyli ("the round one"). When Strongyli's volcano erupted catastrophically around 1650BC, the island split initially into three separate parts. Together, they now form the walls of a massive, fragmented crater enclosing a central lagoon that was created when the middle of the original landmass collapsed into the sea. Subsequent underwater eruptions (the most recent in 1570) threw up the two further islands – Palia Kameni and Nea Kameni ("Old Burnt Island" and "New Burnt Island") – that complete the archipelago.
Unsurprisingly, given its history, Santorini has long been mooted as a possible model for the mythical lost continent of Atlantis. As you look down on it from above, it's hard not to feel drawn to that legend. Every contour of the landscape looks as though it has a story to tell – and the flat blue sea hints at hidden worlds still lost beneath its depths. But the atmosphere is far from melancholy. As the aeroplane begins its descent, a dazzling mosaic of colour comes into view. You see that the grey and red rock face of the crater – the caldera, from the Greek for "cauldron" – is studded with windmills and the island's trademark blue-domed churches. Perched high above them, on the sheer granite cliff-tops directly overlooking the lagoon, an enchanting terrace of sugar-cube settlements runs along the rim of the caldera like a ribbon.
Despite originally being part of the same whole, the three islands encircling Santorini's lagoon are intriguingly different in character. Tiny Aspronisi ("White Island") has no settlements at all. It simply sits silently on the water, like a little white tablet. Thirasia, the second-largest island, is well worth a visit. Rugged and undeveloped, and with a charming eagle's nest of a capital that can be reached only on foot or by donkey trail, it provides a sleepy miniature of how island life must once have been for the whole of Santorini, before the advent of package tourism in the 1970s.
But it's to horseshoe-shaped Thira – the largest of the trio of islands, with 69km of coastline – that most visitors flock. For sun-worshippers, the southern and eastern coasts offer vast black-sand beaches and (in the more commercial resorts such as Kamari) as many cocktail bars and water sports centres as anyone could reasonably hope for. For others, it's the spectacular amphitheatre of the caldera itself, and its cosmopolitan mountain villages, that prove the irresistible attractions. Santorini sunsets, viewed from the caldera, are said to be among the most beautiful in the world – a glorious explosion of colour. The horizon glows, the cliff face lights up in a wash of pinks and purples, and the whole of the sea and sky seem to catch fire, melting into layers of crimson and liquid gold.
Two key places to visit on the caldera are the small town of Fira, on the west of the island, and the village of Oia in the north. Fira is Santorini's capital and, as a popular destination for day-trippers from cruise ships, one of the busiest spots on the island. Flower-filled, pretty, and packed with warrens of little side streets cobbled with black lava stone, it still manages to retain much of its original character. But it's undeniably commercialised. The main square of Theotokopoulos overflows with fast-food cafes and tourists, and the alleyway Odos Ipapantis – lined with jewellery and craft shops (some of them very good) – is sign-posted "Gold Street" in recognition of its appeal to souvenir-hunters. Further concessions to tourism include a cable car linking the town with the small harbour of Gialos at the foot of the cliffs, some 260 metres below. Alternatively, a fleet of brightly liveried donkeys, festooned with beads and bells, is on hand to ferry visitors up and down the winding footpath carved into the cliff face – a daunting zig-zag of almost 600 steps.
If this is all a bit much for you (which I'm afraid it was for me), the good news is that the bustle of Fira is easily left behind, by continuing northwards along the town's main thoroughfare. The cobbled walkway opens up beyond the cable car station into a cliff path that leads along the lip of the caldera to the adjacent villages of Firostefani and Imerovigli. The gentle 30-minute uphill climb to Imerovigli (three kilometres from the centre of Fira) is a delight. The path winds through swathes of wild flowers and fig trees, and swifts skim overhead. To your right are clusters of pretty houses painted in pastel pinks and lemons, and a colourful rabbit-warren of hole-in-the-wall art galleries, craft shops and jewellers' studios (where things cost half the price of the wares on sale in Gold Street). To your left, a narrow white-washed wall is sometimes the only thing that separates you from the sheer drop to the lagoon below. Out at sea, cruise ships wait like stranded whales as Lilliputian tenders buzz back and forth with their cargos of passengers. But they seem a world away.
At 360 metres above sea level, Imerovigli is the highest point on the caldera. Its name means "daytimeV C lookout", as it was once a key vantage point for the islanders to watch out for pirates. Nowadays, it's home to an array of boutique hotels, all built – as conservation laws require – in the style of traditional cliff houses, with rooms burrowing into the rock-face and spilling in terraces down the cliffside. It also boasts a range of family-run tavernas, including Dionisis' Imerovigli Taverna. Most have wonderful sea views, and all offer fresh fish dishes alongside Santorinian specialities such as domatokeftedes (tomato fritters made with the island's famous miniature tomatoes) and fava (a yellow-pea paste served with lemon and chopped onions).
As an alternative to central Fira, Imerovigli is an attractive place to stay. I spent a dreamy couple of nights there on my little terrace, soaking up sunsets and watching crows and kestrels chase their shadows across the speckled stone face of the mountainside. On the morning after the rain the sea shimmered. Billows of moisture pulsed up from the water and curled around the hotel. I literally had my head in the clouds.
For the remainder of my visit, I based myself in Oia (pronounced Ee-a). Formerly a major maritime trading centre, it's entirely picturesque and is rightly celebrated as the jewel in Santorini's crown.
A gorgeous jumble of cave houses, originally built for the families of sailors and fishermen and painted in traditional whites, blues and ochres, jostle cheerfully alongside the imposing neo-classical mansions of former sea captains. Many of the smaller houses have vaulted roofs – another distinctive feature of Santorini's architecture.
Oia contains some of the island's most exclusive cliff-top hotels – I stayed in a breathtakingly beautiful place called Mystique – as well as a chic parade of shops and galleries that run the full length of the marble-paved street. Yet somehow it has retained the quirkiness and laid-back charm that make it so delightful. In the evenings the marble walkway is crowded with sleeping dogs, children playing ball games and family groups dressed up for their regular volta, or evening stroll. And in a warren of streets below the village's cathedral there's an authentically tatty village square, undiscovered by many visitors, where locals gather around bottles of ouzo in rambling tree-shaded tavernas. From here, Santorini's sunsets are even more dramatic than those seen from the designated viewing terrace at the tip of the village. Even the chaotic wiring and loose cables that criss-cross the square becomes part of the experience. Drenched in red light, the telegraph poles branch up into the heavens like tridents.
As is the case with Fira, Oia is connected by steps to the coastline below. Nearly 300 of them (from near the Skala restaurant) take you down to the small harbour of Armeni Bay. Even nicer is the descent (with slightly fewer steps) to lovely Ammoudi Bay. (Ammoudi is also reachable by car or taxi via a rough road, if you want to give your feet – or the donkeys – a rest.) This was probably my favourite discovery – a picture-perfect enclave, with brightly coloured fishing boats and a string of tiny bars and fish tavernas clinging to the quayside. High above you, the white coronet of Oia glitters on the cliff-top. At sea level, a narrow footpath winds around the headland, leading to a small beach with red and black pebbles.
No visit to Santorini is complete without a trip on the water, and there are plenty of small skippered boats for hire from Ammoudi. A number of larger tourist boats also operate from Athinios – the main port of the island, some 11km south of Fira. It was from Athinios, on the final day of my visit, that I made what was probably the most atmospheric trip of the stay – a crossing by traditional sailing caique to view the blistered black wastelands of the two Kameni islands in the centre of the lagoon.
It felt like a voyage into history. The formation of Nea Kameni, following the underwater explosions of the 16th century, brought the crater of Santorini's volcano back up to the surface after more than three thousand years. And although there's been no volcanic activity of note from either island for well over 50 years, they still seem strangely threatening – ominous heaps of alien stone huddled together incongruously on the calm blue water, a living memorial to Santorini's vanished past and an ever-present threat to its future.
Peering into the crater of the volcano itself was an odd anti-climax – no flickering inferno or roaring flames, no smouldering clouds of sulphur gases, no devils with pitchforks. But down on the shoreline, standing alone on an ash-path surrounded by huge black boulders and with only the sound of the seagulls for company, I felt as though I was on the edge of the world.
Despite the deep blue of the sky, a fresh wind was starting to ruffle the water's edge and a few small rain-clouds appeared to be forming. But then I remembered. No – not rain. Precipitation.
The writer travelled to Santorini with Sovereign Luxury Holidays (0871 200 6677; sovereign.com) which offers a range of packages to Santorini. A one-week stay at Icons hotel in Imerovigli starts at £1,281 per person, including return Thomson flights from Gatwick, private transfers and breakfast. A one-week stay at Mystique in Oia starts at £1,715 per person, on the same basis.
Santorini is served by Thomas Cook Airlines (0871 230 2406; book.flythomascook.com) from Gatwick, Manchester and Newcastle; Thomson Airways (0871 231 4787; flights.thomson.co.uk) from Gatwick and Manchester; and easyJet (0905 821 0905; easyJet.com) from Gatwick.
To reduce the impact on the environment, you can buy an "offset" through Abta's Reduce my Footprint initiative (020-3117 0500; www.reducemyfootprint.travel).
Icons Hotel, Imerovigli (00 30 228 602 8950; santorinicons.gr).
Mystique Hotel, Oia (00 30 228 607 1114; starwoodhotels.com).
Eating & drinking there
Imerovigli Taverna, Imerovigli (00 30 228 602 4190).
Skala Restaurant, Oia (00 30 228 607 1362).
Greek National Tourist Office: 020-7495 9300; gnto.co.uk