She was walking down the street in Monrovia, Liberia, feeling angry. Then she and her friends heard singing. It was gospel music. They followed the sound right into a church.

“It sounded like a Baptist church choir, just like home,” remembers Carolyn Stallworth, 65, of Rochester Hills, Mich., of that trip in 1988. She and her friends were furious because they’d had to surrender their passports upon arrival in the African dictatorship. But when they heard the choir practicing at the Providence Baptist Church, their mood lightened.

“The next morning, we went to church there,” she says. “Not only did they sing the gospel spirituals, but the United States Marine Band also played there, and the U.S. ambassador was there.

“Hearing those spirituals on the street that day, just standing outside, that was an amazing experience.”

Some travelers take mission trips. Some take journeys of faith. Some take architecture tours of world churches.

But sometimes, regular people on vacation just happen to decide to attend a religious service — sometimes not even of their own faith —and it sticks with them forever.

“I think that when you travel, the very act of being taken out of your own environment opens you to new experiences. Somebody said, ‘We go through life sightless among miracles.’ And in part, that is because in the routine of our lives we stop seeing what is going on around us,” says Stuart Matlins, editor of How to Be a Perfect Stranger (Sky Light Paths, Fifth Edition, $19.99), a guide to navigating religious services of all types. “When you are in a foreign or different environment, suddenly all your senses are heightened. You see the unusualness of life. It’s not unlike witnessing miracles.”

Matlins is Jewish, but he has attended multiple services around the world, from cathedrals in Frankfurt and Barcelona to a mosque in Pakistan and a synagogue in Krakow.

“Sit in the back is really the best advice for anyone going to any religious service with which they are unfamiliar,” he says. “In every circumstance, sit in the back, and you can’t go wrong.”

It takes a leap of faith to attend a religious service that is not your own. Even services of one’s own faith can have twists.

But often, the experience is so vivid that it sticks with travelers.

Once, far from home and near Denali National Park in Alaska, Dennis Lakomy and his wife sought a church service — and ended up at a tiny Catholic chapel with 14 parishioners and no regular priest.

“It looked like a small home or a large living room, no pews, no anything,” recalls Lakomy, 60, of Lake Orion, Mich.. “They had a visiting priest who would come every once in a while, but he wasn’t available every Sunday, so the day we went, the parishioners held a service on their own and distributed communion. There was a guitar player, and we were able to stay after and just talk to the members. They recognized we were from out of town. That was in August 1990, but it stuck with me so much.”

For Richard Shook of Bay City, Mich., the mass he went to in Xi’an, China — in Chinese — was as impressive as seeing Xi’an’s famous terra cotta warriors.

The doors remained open during the February service “so everyone remained in their heavy coats — even the priests wore them under their vestments,” says Shook, 70. “The church seated maybe 250 people and was full a half-hour before mass started — and as people continued to arrive, they brought out little blue plastic stools to fill every available space.”