OIA, Greece – The scorching Mediterranean heat and my flirtatious sciatica are beginning to make our half-hearted quest to find this island town’s old fortress short-lived at best. Especially when we spy the English-language sign for a potentially far more interesting amusement: the Santorini Observatory. A little sky-gazing in the afternoon? And for only four euro? Too good to pass up.
 

“How much is that in U.S. dollars?” I ask my traveling companion who is already punching numbers into her cell phone's currency converter.
 

“Four-and-a-half bucks -- the dollar is strong with this one,” she says.
 

The signage points down a narrow, stepped walkway. Before long we arrive at a cerulean-tiled terrace with potted geraniums and, aimed toward the heavens, a trio of research-grade telescopes that includes a German-engineered Meade 20-inch MAX2. In the opposite direction, nearly 1,000 feet directly below us and the observatory's cliff-top verandah, half a dozen mega-yachts moored in the harbor dot the sweeping view of the cobalt-blue Aegean Sea. Surrounding us is a pleasant jumble of dazzling white "sugar-cube" cave bungalows, or skafta, and blue-domed Orthodox churches for which Santorini is best known. The identical blue hue accents everything on the island – door frames, window boxes, tavern tables, you name it.
 

Way too much pretty on this island. Time to stare into the sun through a $36,000 telescope.
 

Astronomers and German expats Cornelia Haertelt and Werner Popp focus their broad smiles on the visitors. “This is our grand opening and you’re our very first customers!” Haertelt says excitedly.
 

Haertelt and Popp, both from Stuttgart, pour cold water for their thirsty guests who are only too happy to huddle beneath the patio table's large umbrella on a sizzling June afternoon.
 

“We’re trying to bring together philosophy and science,” Haertelt says. “We are all made of stardust – we are all like little stars on Earth."
 

More than 2,000 years after the Greeks Pythagoras and Ptolemy invented mathematics-based astronomy, the observatory’s first official customers are soon taking turns ascending wooden step-stools to gaze at the sun with ultraviolet safety filters. Any fears I have that our German hosts are determined to literally blind us with science evaporate as we watch swirls of dark sunspots inch across the surface of our solar system’s blazing star.
 

“OK, this is awesome,” says my traveling companion.
 

The white-bearded Popp smiles. “The clear skies and low ambient light of Santorini,” he explains, “makes the island ideally suited for gazing at stars by night and the sun by day.”
 

Day or night the atmospheric village of Oia (pronounced EE-yah), perched high above the sea, is surely the little star of Santorini, Greece’s island of 7,000 residents located in the southwestern edge of the Aegean. Quiet mornings find elderly, white-haired women in black housedresses toting small grocery bags of bread and colorful fresh vegetables up winding flagstone alleyways. Cats nap in cracked doorways which offer rare peeks inside sundrenched Mediterranean courtyards, where clothes and pillow cases hanging from laundry lines catch the sultry winds blowing off the coasts of Turkey and North Africa.
 

Sunlight warms the village’s homey art-gallery terraces and the patios of little shops of tchotchkes. Couples and youngish singles yawn awake at sidewalk tavernas. Some are busy reading Ekathimerini, the English-language Greek newspaper. Others tend to their hangovers with eye-opening gulps of thick Greek coffee or sips of anise-flavored ouzo. And so the day begins.
 

Then it’s time for a nap.
 

FIRA NOT, PLATO
 

Santorini might lack the architectural drama of Rhodes’ acropolis or the Sapphic lore of Lesbos, but the island is at once simple, sensual. And mercilessly photogenic. Over the decades Greek islands have stolen the show in dozens of movies ranging from “Zorba the Greek” (filmed on Rhodes) and “Captain Morelli’s Mandolin" (Cephallonia) to the Mykonos-based “Shirley Valentine,” the tale of a Liverpool homemaker’s midlife self-renewal after battling marital ennui and the empty nest.
 

But it was the menagé à trois-themed flick “Summer Lovers” in 1982 that gave many Americans their first glimpse of Santorini. Today the near-flawless weather of this stunning Aegean jewel keeps the island’s international airport hopping with European and U.S. travelers during the May-October tourist season. This poster-perfect isle of volcanic black-sand beaches is also a favorite among daytrippers and weekenders who arrive at the port of Skala by cruise ship or overnight ferry from Athens.
 

To reach the capital of Fira, travelers arriving by sea take the three-minute Swiss funicular or opt to ride a donkey up a 2,000-foot high zigzag of switchbacks. A few hearty souls even choose to walk the 580 steps. Either way, skip the donkey ride on the way down in the late afternoon. Weekend warriors have been known to break into cold sweats when their peckish beast of burden, lured by daily feed time at the waterfront dock, begins scrambling downhill. Not for the feint of heart, sir.
 

Well-pedestrianized Fira buzzes with the rattle and hum of tourists and mopeds. Peaceful outlying neighborhoods line Fira’s Agiou Mina Street, which runs south along the raised lip of the caldera, or sunken volcanic rim. Here open-air tavernas serve up a little quietude alongside such local staples as fava bean soup, melitinia (cheese and honey pies) and tomatokeftedes (fried “tomatoballs” mixed with bread and onions).
 

A daily special not on the menu are the free panoramic views of the Aegean Sea and Santorini’s outlying sister islets, Thirasia and Aspronisi – all that remains of the caldera. As history reminds us, one of the most catastrophic volcanic eruptions in the past 10,000 years occurred here in 1450 BC. When the volcano collapsed, wiping out half of the island, all that was left behind was the crescent-shaped Santorini – and endless speculation that there beneath the sea lie’s Plato’s mythological Atlantis.
 

Nearly as legendary are the sunsets. Locals and tourists alike flock like homing pigeons from all over the island to Oia village, nine miles north of Fira, to enjoy a bird’s-eye view of the remains of the day: a purple Mediterranean sky slowly downshifting into heavenly crimson behind the Aegean horizon. Gathered this evening on the rooftop of Franco’s Bar is a sunset-savvy international crowd of mostly Brazilian, French and Australian travelers watching the transition to dusk as a Chopin etude plays on a stereo in the background.
 

By 11 o’clock the bar revs to life with boinky-dink-a-doink bouzouki music and, later, Euro-disco and its hypnotic rhythm tracks reminiscent of the sound of midnight metros. “When the fun gets going,” Swiss expat Johann Kunzler says grinning, “it doesn’t let up until five in the morning.”
 

Fortunately, Oia’s maze of narrow, donkey-wide walkways with eight-foot-high walls helps protect party animals tumbling home at sunrise from veering too far off course. And sometimes not. But the worst that happens to us one early morning is we mistakenly descend the hillside of flagstone steps that leads from Oia down to the water’s edge and the fishing village of Ammoundi and its romantic outdoor taverns. Tucked like a lover’s whisper at the bottom of the cliff, this Greek comma of sleepy shoreline bliss has been luring travelers on unchartered journeys for thousands of years.
 

Just ask Ulysses. Or Shirley Valentine.
 

SCULPTURE ON HOLIDAY
 

Heading south leads deep into the rural heart of Santorini’s wine country. During August harvest visitors to the Buttari vineyards in Messaria roll up their pants for a little grape-stomping fun to help produce some of the island’s well-regarded white and red wines. Nearby, Akrotiri, a prehistoric Pompeii buried beneath volcanic ash and first discovered in 1967, is still under excavation and open to the public. History buffs short on time should instead hit Fira’s Archaeological Museum to explore a far superior collection of Bronze Age jugs, amphorae and ochre frescos culled from this 3000 BC Minoan colony.
 

Eventually the two-lane road ends at the bucolic seaside resort of Perissa and its clothing-optional black-sand beaches adorned with stunning reminders of Greek culture’s millennia-old devotion to the human form.
 

“They look like sculpture on holiday,” my traveling companion says surveying a beachscape of virtually perfect au natural physiques.
 

Midnight in Perissa offers up a far less artful shoreline moment: Turns out “secluded romantic beach” may refer to the absence of other beachgoers after dark but not the stealthy, late-night lobster hunter, with catch in hand, who unbeknownst to us casually walks directly past our little beach blanket bingo.
 

“Kalispera!” he says merrily in Greek for “good evening.”
 

Friendly people.
 

Next morning the quiet drive back to Fira to drop off the open-air rental Jeep leads past now-familiar homes and churches trimmed with the identical cobalt tint of the sea. It is agreed that despite this island’s wondrously raucous bouzouki bars, delicious tomatokeftedes and ancient history, it is the color of this Aegean paradise that will likely linger long after journey’s end.
 

“It’s like everyone on the island passed around the same bucket of blue paint,” my passenger says grinning.
 

Wistfully, the color is dubbed “Santorini blue.” And, no, Home Depot doesn’t carry it.