It is here, millions believe, that the Virgin Mary spent the final days of her life, having been escorted here in AD 37 by St. John the Evangelist.
Meryemana (Mary's House) is a tranquil spot, surrounded on all sides by lush greenery. "There's an atmosphere here, a real sense of peace," says Australian Natalie Jose, who is leading a small tour group to the site.
"I have never been here before and I really didn't expect this," she says.
As a cat lurks in the shade, we follow a nun in blue habit through an arched doorway and into the chapel area, filled with four rows of pews and flickering candles. The altar has a small statue of Mary in an alcove and the stone floor is covered with rugs.
A right turn leads to an even smaller room, with benches where you can pause for a moment's contemplation. Then it's back out into the bright sunshine and the fresh air of Bulbul (Nightingale) Mountain.
Some steps lead down to a terrace and a series of faucets where you can sip water that supposedly has curative powers. Then there's a wall with a series of metal grates hung on it. Hundreds of messages and petitions to Mary are tucked into them, written on handkerchiefs, paper tissues, even a J Cloth — mute tribute to the quiet power of this place.
Another Australian visitor, Tory Rands, tells me she is not particularly religious but scribbles a message anyway, and finds a spot for it. "You never know," she says with a smile.
Yet it's quite possible Mary never lived here.
The Bible tells us that Jesus entrusted his mother to John's care, but there's no direct evidence about what happened to Mary after Jesus' death. There's a tradition that she accompanied John to Asia Minor, although many scholars believe she died in Jerusalem.
In the 19th century, however, an ailing, feverish German nun called Anne Catherine Emmerich had visions of a small stone house near Ephesus. In 1891, researchers found a house that matched her descriptions and was already revered by local residents. She also said she saw Mary's grave; this has not been found.
In the 20th century, successive popes have declared Mary's House a place of pilgrimage for Christians. Pope Paul VI celebrated mass there in 1967 and Pope John Paul II visited the site in 1979.
But Muslims as well as Christians come here in considerable numbers — the Muslim faith recognizes Mary as the mother of a major prophet. Of Turkey's population of about 68 million, 99 per cent are Muslim.
Turkey's links with Christianity stretch back to the earliest days of the church, and nowadays more than 20 Christian denominations find a home here. Evidence of the country's role in nurturing Christianity are all around. For example, what the Catholic Church recognized in 1963 as the world's first cathedral — a cave known as St. Peter's Grotto — is in Antakya (the old Antioch), in the southeastern tip of the country.
Visitors to Turkey may not venture that far, but Ephesus, with its marble temples, impressive library and 25,000-seat theatre is a must-see. And the ideal base is Selcuk, about 3 1/2 kilometres away.
Jose said Selcuk still feels like a typical Turkish village.
"You can wander the back streets and see women sitting on crates making manti (meat dumplings, topped with a warm sauce of yoghurt, garlic and chili oil) or wearing baggy, Turkish-style clothes." Selcuk, in fact, contains the ruins of the Basilica of St. John, the once-great church constructed in the 6th century by Emperor Justinian over what's believed to be the burial site of St. John. It's a short stroll from the centre of town, on the slopes of Ayasoluk Hill.
The tomb of St. John is surprisingly unadorned — just a simple slab surrounded by pillars. You expect more pomp and circumstance.
Selcuk also contains an outstanding museum with a wealth of artifacts from Ephesus and a sculpture of Artemis that is thought to have come from the Temple of Artemis close by.
The temple was once one of the Seven Wonders of the World. All that remains is one pillar amid marshy ground with a stork nesting on top, and the single stump of another.
Ephesus itself remains the tourist magnet, however. Like millions of tourists before him, the Pope will no doubt wonder at the Library of Celsius, built circa AD 110-135, and once the third most important library in the Mediterranean world.
And it was in the amphitheatre here that St. Paul preached to Ephesian silversmiths, who responded by rioting.
The ruins are about two kilometres long and take about a couple of hours to cover in some detail. Smart guides, such as Nail Usun, will start you in the opposite directions to the crowds.
Usun, who has been a guide here for three decades, is a small man with a large personality.
He'll rattle off all the history — how the broken pillars and marble walkways that we see today were part of a city that was founded in the 4th century BC by one of Alexander the Great's successors; how the Persians took it over for a while; how it was eventually enfolded into the Roman Empire and how the city declined as its harbour silted up.
He'll mention that two great councils of the early Christian church were held here, in AD 431 and in AD 449.
He will tell you about two temples built to honour visiting emperors — the Temple of Domitian and the Temple of Hadrian. He'll show you the Gate of Hercules and tell you to stand between the two pillars and make a wish. It's truly wondrous and, amazingly, only about one-third of the site has been excavated.
But Usun will also issue precise orders about where to stand to take "professional" pictures and tell you slightly risqué tales that one imagines the Pope is unlikely to hear.
An eternal flame, tended by Vestal Virgins, once burned on the Altar of Hestia Boulaia, Usun tells us. They worked hard, from the age of 10 to 40, he says.
"Early each morning they were checked by the priests and if they had had some relations with other priests, if they were pregnant or had lost their virginity, they were buried alive.
"If they were still virgins at the age of 40, they were retired from their work and given a sum of money and they could buy any young man to get married.
"Nowadays, it is said that life begins at 40 and now you know the reason why."
We wander to the public latrines — multi-seater, narrow stone benches above open troughs — and Usun seats himself comfortably before continuing.
"To sit on the cool marble in summer was so comfortable," he says, with a grin.
"But in winter the marble got cold, frozen.
"Some of the guides say that they called their wives, fiancées and their female slaves to sit first and warm it up. They say that (the English expression) `ladies first' comes from here, but that is a joke."
We walk down the Marble Way, sun bouncing fiercely off the surface of the road.
Across the way from the library, Usun shows us a footprint etched into the marble, along with a heart, a cross and the portrait of a woman.
It is an ad for a brothel, which was apparently connected to the library by a secret, underground passageway. What looks like a cross is coded directions to the bordello, Usun says.
"She is saying, if you need a professional one who knows all the techniques, keep going along this marble way, turn left and come to me if you have cash. But no money, no honey.
"Anyone whose left foot was smaller than hers couldn't enter. They were under 18 and too young. They went to the library to read the theory and to prepare for the final exam."
And, being Usun, he can't resist a final joke:
"Some guides say that she took American Express and that her mobile phone number is written there. This is not true."
