Thomas Wilkinson removes his hat before entering the Basilica of St. Patrick’s Old Cathedral in Lower Manhattan. Beneath the arching, cast-iron beams and in front of the altar, he crosses himself and turns to the group he is leading on his Catacombs by Candlelight tour.

Wilkinson explains that the baptism scene in The Godfather was filmed here; Sofia Coppola was the baby. The group exits a side door at the front of the church and descends narrow stairs to the lower level. Wilkinson distributes electric tea lights before the wooden double doors that lead to the most anticipated part of the tour. A hush overcomes the group, and Wilkinson opens the doors.

Until June, the Old Cathedral’s catacombs—the city’s only subterranean cemetery with recesses for tombs—were not open to the public. But now visitors can take one of three daily tours with Tommy’s New York, Wilkinson’s company and the Old Cathedral’s exclusive tour partner. Wilkinson, 47, a lifelong Staten Islander and parishioner, tells little-known stories of the Old Cathedral, which was the center of Catholic New York before St. Patrick’s Cathedral was built uptown.

“I never foresaw that a church could be a potential business partner like this,” Wilkinson said. “It’s an eye-opener because people get so excited about the rediscovery of pieces of history down here.”

Wilkinson first met the Old Cathe­dral’s current monsignor, Donald Saka­no, at an Italian American organization’s meeting in the neighborhood of the cathedral. The monsignor realized Wilkinson’s tour business could fulfill a need: locals and tourists often came by the Old Cathedral asking for tours.

Wilkinson, who founded his company in 2015, now focuses exclusively on the Catacombs by Candlelight tour. He prices the tours at $35 per person and  splits the proceeds evenly with the Old Cathedral.

The cornerstone of the Old Cathedral—the second-oldest Roman Catholic cathedral in the United States, after Baltimore’s—was laid in 1809. From 1850 to 1879, it was the seat of the Archdiocese of New York. Some of New York’s most prominent Catholics are buried there. The cathedral, still a parish church, was where film director Martin Scorsese served as an altar boy.

If the walls surrounding the Old Cathedral could talk, they would be fluent in Gaelic, Italian, Spanish, Mandarin, and Cantonese, thanks to the immigrants who have worshiped within them. The walls might explain that they were built in the mid-1800s as protection from anti-Catholic mobs.

“This church has been a silent witness to the changing times of this neighborhood,” said Frank Alfieri, director of the cemetery and columbaria and head of development at the Old Cathedral. He trusts Wilkinson to tell its story: “He’s done his due diligence. He’s researched everything. He documents everything.”

But Wilkinson also tries to make the history fun. The wisecracking tour guide mixes stories about Catholic traditions with general New York history, pop culture, and architecture facts. “It’s infotainment,” he said. “I’ve tried to take as much of the religion out of it so it can have mass appeal, no pun intended.”

He guides about 15 people per tour per weekday and as many as 38 people per tour on weekends. They snake through the two graveyards, shuffle into the church, climb to the 1868 Henry Erben pipe organ in the balcony, and explore the catacombs.

Within the catacombs, the air is warmer. Tourists slowly file into the dim space, some holding up their electric tea lights to read the inscriptions on the vaults, which hold up to 12 corpses. Those expecting medieval catacombs with dirt floors—“Game of Thrones catacombs,” in the words of Bob Weisser, a recent tourist—may be surprised to see how modern the Old Cathedral’s catacombs seem, with clean lines and pristine tiled floors.

After corralling the tourists wandering down the darkened halls, Wilkinson brings alive the people buried in the vaults. He projects photos on the wall of 1032 Fifth Avenue, a stately mansion that was once the estate of Countess Annie Leary, a prominent philanthropist in the early 20th century.

Explaining that 12 members of the Delmonico family are buried nearby, he projects an old menu from Delmonico’s restaurant, credited with inventing eggs Benedict. Wilkinson points out the final resting place of John Kelly, the former state representative and well-heeled boss of Tammany Hall, and perhaps the most famous resident of the catacombs. Kelly’s family, Wilkinson adds, still stops by to pay respects.

He takes the group to the vault of Thomas Eckert, a confidant and bodyguard of Abraham Lincoln. Eckert’s is the only vault that tourists can enter. Wilkinson calls attention to the aqua Guastavino tiles lining the inside of the vault—the same tiles found at Grand Central Station and Ellis Island—and the Edison and Co. light fixtures hanging from the ceiling.

But the catacombs are not home only to those already dead. Around the perimeter of the catacombs floor are wooden boards, placeholders for the 3,000 niches to be installed. Niches hold one to two urns of cremains. Five years ago, the Old Cathedral revived the Catholic tradition of burying Catholics on the grounds of their church, and the revenue from the sale of burial spaces funds the restoration of the church and cemetery.

There is already one gray, granite columbarium—a room for the niches—in the catacombs, and two others are in the graveyard. Individuals can purchase a niche for $7,000 to $10,000—a real estate bargain in the neighborhood, where the asking price for a townhouse across from the Old Cathedral is $25 million.

“For some, it’s an opportunity to be laid to rest alongside special figures of New York City history,” Wilkinson said.

Although Wilkinson has made sure the tours can be appreciated by non-Catholics, Alfieri hopes they will draw people into the Catholic faith and further involvement with the Old Cathedral.

“It becomes a function of evangelization,” he said, “bringing people into a very sacred place, sharing histories of people buried here who were extraordinary Catholics who supported the church.” —Religion News Service

A version of this article, which was edited on January 12, appears in the January 31 print edition under the title “Old Catholic cathedral in New York City offers tours of catacombs.”