Of all the prophecies in the Book of Revelation few are more startling than the Four Horsemen, a fiery stampede sent to signal the end of the world. Yet the Greek island of Patmos, long worshipped as the place where St John received his apocalyptic visions, is more heaven than hell.

Climbing the hill towards the Cave of the Apocalypse I pause to catch my breath, a switchback affording a shady alcove.

In the distance stretches the Aegean Sea, an azure scarf ringed with green hills, all plump and chubby from the winter rains. Below, a tumble of sugar-cube houses glint in the morning sunlight. Inside, the candlelit grotto is dusky and damp, its ceiling strung with lamps representing the seven lamps of fire.

“I am the Alpha and the Omega, the beginning and the end,” whispers our local guide Nicholas Alafakis, repeating the haunting line from the last book of the Bible. He points to the fissure where God spoke to John, and the cleft where the saint rested his head. Whether you are spiritual or not, it’s hard not to be moved by such dedication.

There is something special about Patmos. Legend has it that the island’s original name was “Litois”, in honour of the goddess Artemis who, together with Apollo, convinced Zeus to bring the sunken island back to the surface. The neighbouring islands of Icaria (after Icarus) and Samos, where Pythagoras was born, put Patmos at the centre of a mystical vortex. Locals will tell you the island vibrates with its own energy.

One thing it doesn’t vibrate with is mass tourism, particularly in early spring. Situated to the north of Greece’s Dodecanese island group, and closer to Turkey than Greece, getting to dolphin-shaped Patmos takes some planning. There’s no airport on the island, a ferry trip from Athens takes eight hours and mega-liners can’t enter the shallow port.

It’s day two when we arrive by tender boat from our ship Celestyal Olympia, Patmos being one of the six ports we’ll visit during our four-night Iconic Aegean cruise with Celestyal Cruises. Living up to the tagline – cruising done differently – we’ll not only visit the popular islands of Mykonos and Santorini, but also the Turkish port of Kusadasi (gateway to the ancient city of Ephesus), Rhodes (in the far-flung Dodecanese islands) and Heraklion in Crete (famous for Knossos, the political centre of the Minoan civilisation).

More like a river cruise, with its frequent ports of call and lack of endless “sea days”, a journey aboard the mid-sized (1664 passenger), Celestyal Olympia offers a mezze-platter of bite-sized delights.

On Mykonos we dine on filo-wrapped feta dribbled with fresh honey, onion pie made with local tyrovolia cheese and sizzling lamb souvlaki served with tzatziki. “Mykonos regains its balance during springtime,” says our waiter, filling our glasses from carafes of house-made wine. “You are seeing Mykonos like few visitors are lucky to do so.”

The authentic Greek experiences continue onboard the Athens-based Celestyal Olympia with cooking, dance and language lessons, an open-air Greek deli, and choice of buffet and la carte restaurants serving a selection of local delicacies. Shore excursions are in-depth and varied, designed to allow participants to delve fully into the local history and culture.

While a programme of nightly shows – from cabarets to Cirque Fantastic – keeps the onboard guests entertained, late-night departures provide more time in port and the opportunity for evening exploration. This is part of Celestyal Cruises’ commitment to providing guests with maximum immersion during a relatively brief sojourn.

Traditionally, high season in the Greek Islands runs from July to September, a time of inflated prices, swarms of tourists and soaring temperatures. In a bid to encourage guests to travel beyond peak times Celestyal Cruises has developed new itineraries extending the season from March to November. It has also introduced an eight-day, three-continents cruise taking in Greece, Egypt, Israel, Cyprus and Turkey during the off-season months of October to March.

From Mykonos we sail overnight to Kusadasi on Turkey’s western Aegean coast, waking to a view of Ataturk Hill with its tumble of sherbet-coloured houses pressed against an Aegean blue sky. The short drive to the ancient city of Ephesus takes us through groves of olives trees and past fields strung with figs and peaches.

The Unesco-listed Ancient City of Ephesus arrives in a rush of broken columns and headless heroes, triumphal arches and marble streets. While much of Ephesus’ history is clouded in mythology, archaeological evidence suggests the site was inhabited as far back as 7000BC. Changing hands between numerous conquerors, Ephesus came under Roman rule in 129BC, becoming the most important trading centre in the Mediterranean. Today, the site holds some of the best preserved Greco-Roman ruins in Europe.

We enter at the Magnesia (Upper) Gate, erected under Vespasian in the first century AD, moving past the small Odeon theatre and commercial Agora. Littered with pillars and pedestals, once boisterous with people, it is now peppered with silent fig trees. On all sides steep hills stand sentinel, flushed in their spring coat of pink Judas trees.

While our guide John Ates is well-versed in archaeology, he also breathes life into the ruins with his stories about Hermes, the Greek messenger god and Nike, the winged Goddess of Victory. “You can see the Nike logo in the ‘swoosh’ of her wings and the folds of her dress,” says Ates, pointing to the relief of the goddess carved into marble.

Strolling the ruins of this once thriving metropolis, we see Amazonian figures carved into temples; a monumental library built to house 12,000 scrolls; a row of terrace houses decorated with frescoes, and a 25,000-seat theatre used for concerts, plays and philosophical discussions. “120 years of excavations and we’ve only uncovered 14 per cent of the original city, says Ates. “Who knows what else is buried here.”

We have more to explore – but for now we are content to sit in the sun and enjoy what Amphitrite, the Greek goddess of the sea, has delivered.