Rhodes: Beyond the crowds lie splendid ruins, secret beaches and an ancient prototype of the EU

Early one summer morning, I picked my way over the knobbly cobbles of the Street of the Knights in Rhodes's Old Town, with the Palace of the Grand Masters behind me and the sea straight ahead, obscured by the sturdy fortress wall that once gave would-be invaders of the island serious pause for thought. The sun rose above the old battlements, steadily raising the air temperature towards 35C, where it would remain for the rest of that day, and the next, and the day after that.

Among the echoes and shadows, the only sign of life was a flock of pigeons breakfasting on something left over from the night before. Passing under a stone bridge that once connected Spain with Provence, I peered through a modern glass doorway into an intimate French courtyard, paused at some wrought-iron railings giving on to a lush Turkish garden, and continued down the gentle slope towards England and Auvergne, passing Italy on the left-hand side.

This exotic journey was real, not imagined. My stopping points were Inns, not countries. Not inns as we know them today, but meeting places for the different nationalities of the Knights of St John, who, having broken off from the Crusades, created in the early 14th century a prototype of the European Union as a bulwark against the forces of Ottoman Turkey, looming mountainously on the northern horizon.

Knights from seven countries – the site of the German Inn has never been traced – built their citadel on the northern extremity of the island, fortified other parts of Rhodes and the Dodecanese with 30 castles, and under the governance of life-elected Grand Masters held the line for more than 200 years until submitting to the enemy's vastly superior forces in 1522.

There wouldn't have been much left of the Inns after that long and terrifying siege, when the few surviving Knights of the garrison were given safe passage off the island by their conquerors. There certainly wasn't much left of the Grand Masters' Palace after an accidental gunpowder explosion in 1856, but a restoration programme that began in the 1930s and continues today has brought one of the Mediterranean's most important medieval sites back to life.

There are museums aplenty at either end of the Street of the Knights (signed in its Greek name, Odos Ippoton), chronicling everything from the foundation of the city of Rhodes, about 2,400 years ago, through the Byzantine and medieval periods and beyond. But a quiet stroll among the buildings of honey-coloured stone, deviating here and there to lose yourself in the maze of interconnecting alleyways and side streets, gives you a keener sense of what it was like to live there than any number of audiovisual presentations.

This is a place of both soaring achievement and thudding calamity, where neighbouring cultures and religions have collided, squabbled and eventually found a way of living together. There are mosques and minarets, art galleries, libraries and theatres; a Christian-built watchtower and a Turkish hammam; a Jewish quarter and Orthodox churches; and expanses of open ground where Hellenistic ruins have been excavated. A dozen riveting volumes of history are condensed into a 90-minute walk – but the sun was getting up, and the picture was about to be utterly transformed.

At the bottom of the street I crossed Museum Square to one of the 11 gates connecting the old town with the new. Through the archway I got my first glimpse of the modern port. Half a mile away, a vast cruise ship was making its final manoeuvres into port. I hadn't believed it was possible to build ships so big; how could such a monster possibly float, let alone move about the Aegean?

And there was more. Along a half-mile stretch of quay, seven other white leviathans were starting to disgorge their occupants, and most of them seemed to be heading my way. By mid-morning, the multi-national invasion force had raided the souvenir stalls, stormed through the undefended walls and taken the Palace, and surged through the Archaeological Museum to gaze upon the naked form of Aphrodite, Rhodes's most eyecatching sculpture. After breaking for lunch, they advanced on the shops and markets in search of gold, silver and leatherwork. In the late afternoon, distant hooters blew and they were gone – to Kos, or Athens, or Venice. The shopkeepers and restaurateurs mopped their brows – and delightedly counted their takings.

Half an hour down the coast, the summer inundation is less benign. Faliraki is the gateway to a strip of sandy beaches, coves and castellated promontories. A few years ago, this seductive package briefly turned Rhodes into the Mediterranean's most popular holiday island, but the development was careless, and the sandy strip turned into a crucible of noise, booze and the pursuit of pleasure on a 24/7 basis. Nothing wrong with that – until the death of a British teenager in a nightclub brawl in 2003 gave Faliraki, in particular, a reputation it has never quite lived down.

Costas, from the car-hire company, made a point of driving me through " Bar Street", which leads to the seafront. "Look, only one, two, three... four bars here now," he counted, "and here at the end of the street is our new police station. There's no trouble here now." The trouble is, there aren't as many tourists as before, and the owner of a beachwear shop complained that business this summer is disappointingly slow.

"The young people – the ones who drink and party – they've moved on," said Costas. "Now they go to Crete or Corfu or some place."

In fact, young people – and older ones, too – are still visiting Rhodes in large numbers, as the cruise ship inundation had demonstrated. Last year, the island welcomed 1.2 million incomers – about a quarter of them from Britain – and although there are times when the narrow roads are clogged with cars, the island is big enough to absorb them. The tourism industry on Rhodes is a mercifully ungreedy monster, requiring only two strips of coastline and the bustling capital for its pleasures. Much of this many-faceted, captivating island remains untouched; a rental car is essential.

One golden Sunday, we used ours to explore the west coast, starting at the ruins of Kameiros, the Greek city destroyed by an earthquake in 142BC. Stopping to hand-feed wandering goats from the car, we lunched at a taverna above a pretty beach, looking across the sound to Halki and its satellite islands, pale blue in the haze.

We then took the inland road towards Mount Attaviros, the highest of the barren mountains that form the island's spine, stopping in the foothills at Embonas for supplies of locally made wine and extra virgin olive oil, before threading our way back to the coast through slumbering villages where the streets are barely wide enough for cars to pass between the houses. At Kritinia, we climbed a 15th-century castle, and further south we discovered a gorgeous beach at Fourni, joining a smattering of families splashing in the sea. As the sun began to fall, we crossed empty moorland to reach the blowsy, hippyish resort of Prasonisi on the southern tip, where surfers and camper vans rule the roost.

At sunset, a bronzed, exhausted, wind-blown family made their way to the campsite's communal washroom. Around dawn, not far up the road, clubbers emerged, equally exhausted, from the Faliraki nightclubs. And further north, cruise passengers would later be strolling around the Old Town, toting their digital cameras and credit cards.

Three sets of modern invaders, drawn to magical Rhodes like the Ottoman Turks, but each contributing in their own way to its survival. For seven months of the year, when the sun shines almost permanently, Rhodes has room for them all.

Traveller's guide

GETTING THERE

The writer flew with British Airways (0870 850 9850; www.ba.com), which flies four times a week to Rhodes from Gatwick. Alternatively, flights are available with Thomas Cook Airlines (08707 520918; www.flythomascook.com) and Thomsonfly (0870 190 0737; www.thomsonfly.com) from a range of UK airports, and XL Airways (0870 320 7777; www.xl.com) from Gatwick.

You can buy a carbon "offset" from Equiclimate (0845 456 0170; www.ebico.co.uk) or Pure (020-7382 7815; www.puretrust.org.uk).

STAYING THERE

Rhodes has plenty of choice.

The writer stayed at the recently opened Hotel Avalon, 9 Charitos Street, Old Town Rhodes (00 30 22410 31438; www.avalonrhodes.gr). Suites start at €230 (£164), including breakfast.

Niki's Hotel, 39 Sofokleous Street, Old Town Rhodes (00 30 22410 25115; www.nikishotel.gr). Doubles start at ¿€50 (£36), including breakfast.

Hotel Isole, 75 Evdoxou Street, Old Town Rhodes (00 30 22410 20682; www.hotelisole.com). Doubles start at ¿€48 (£34), including breakfast.

EATING & DRINKING THERE

The writer recommends Dinoris Fish Restaurant, 14a Museum Square, Old Town Rhodes (00 30 22410 25824).

Myrovolies, 13 Lachitos Street, Old Town, Rhodes (00 30 22410 38693).

MORE INFORMATION

Rhodes tourist office: 3 Plotarchou Blessa Street (00 30 22410 74555; www.rodosisland.gr).

The Greek National Tourist Office in London is contactable on 020-7495 9300, or by visiting www.gnto.co.uk.