"I remember thinking: 'The tomb of Matthew? I thought he was buried in Jerusalem or Italy or somewhere like that,'" Bissell recalled. But Kyrgyzstan, he soon learned, also had a claim on the apostle's final resting place.

The woman led Bissell to the ruins of a monastery next to Lake Issyk Kul, where according to local legend the saint's relics were transported by Armenian monks in the fifth century. It was a small marker in the remote reaches of Central Asia.

"That planted the seed," Bissell said. He began to wonder about the rest of the apostles, and discovered that many of them ended up in pretty strange places.

Bissell, a highly regarded travel and nonfiction writer, is at the American Academy in Rome this year working on a book on the tombs of the Twelve Apostles.

Actually, as Bissell pointed out, it's 13 Apostles – Matthias was chosen to replace Judas Iscariot after Judas betrayed Christ and committed suicide.

St. Matthias, like most of the apostles, is known mostly through legend and tradition. His relics were said to have been brought from Jerusalem by St. Helena, the mother of Emperor Constantine, and given in part to an abbey church in Trier, Germany. So Bissell made a pilgrimage to Trier and spent the day with a priest, who happened to be named Matthias.

"This priest had a really beautiful way of looking at it," Bissell said. "He said, 'I don't really know if these are Matthias' bones, but this church is here, and I am here because someone very early on believed these were the relics of one of the apostles, and that's a tradition worth preserving.'"

Bissell said one of the most haunting spots he visited was Aceldama near Jerusalem, where Judas is said to have hanged himself. Unlike other historical places in and around the holy city, this one had no gift shops and no tour guides. A thin and not very worn path leads to the site.

"There's absolutely nothing there. There's this dead tree in the middle of a little clearing, and there are caves all around it where the apostles supposedly hid," Bissell said.

He spent fours hours at Aceldama and saw only one other person, a Palestinian shepherd. It was, he concluded, "very, very spooky."

Bissell is not out to authenticate tombs or settle debates over which place has the most legitimate claims to the relics of the apostles. But he does find some traditions more believable than others.

He said it was significant, for example, that 100 years after St. Peter died, people believed he was buried in a spot on the Vatican hillside, where the basilica was later built.

Bissell said it's harder for him to take seriously the legend that the bones of St. Bartholomew were lost at sea, somehow washed ashore in southern Italy and ended up in a Rome church, where they are now venerated.

The apostles roamed far and wide, and some were buried far from their homes. St. Thomas, for example, evangelized in India and tradition says his first tomb was there. The bones of the apostles have made equally long journeys, sometimes back and forth over entire continents.

There are several reasons for this, Bissell said. In many places, local Christians feared desecration of the remains, particularly by Ottoman soldiers. Sometimes monks and religious setting out for distant lands brought relics as a form of "portable holiness." And sometimes church leaders in Rome had relics sent as a gift to young Christian churches.

Bissell said that in researching his book he's especially interested in what kind of devotion the apostles have inspired in their burial locations.

"You'd think having an apostle in your church would automatically equal a stream of pilgrims. But some of these places are really woebegone. Some have very active cults, and some have not much really going on," he said.

St. Peter's is obviously a place of great devotion. So is St. Andrew's Church in Patras, Greece, where Bissell said he watched Greek college students sending text messages while they were waiting in line to kiss the coffin that holds St. Andrew's head.

On the other hand, the Church of the Holy Apostles in Rome, which holds relics of Sts. Philip and James, draws few pilgrims. When he visited, Bissell said, the church was frequented mainly by street people coming for charity.

Bissell said the local priest at Holy Apostles told him he was the first person in his eight years there who ever came asking about Sts. Philip and James. Their bones, after earlier sojourns in the ancient cities of Hierapolis and Constantinople, are preserved in a crypt below the main altar.