Timothy Beal’s epiphany occurred on a drive from Washington, D.C., to Cleveland.

Near Frostburg, Md., a hulking assemblage of reddish girders four stories high suddenly loomed alongside Interstate 68. A bold, blue sign explained:

“NOAH’S ARK BEING REBUILT HERE!”

The following summer, Beal, a religion professor at Case Western Reserve University, found himself in a rented motor home with the wife and children, exploring the Frostburg ark and other astonishing spiritual tourist attractions. Among them: Kentucky’s cheesy and oddly named Golgotha Fun Park (a miniature golf course, now defunct); the world’s largest Ten Commandments display; and, the world’s largest rosary collection in Stevenson, Wash.

Beal’s odyssey has wrought “Roadside Religion: In Search of the Sacred, the Strange and the Substance of Faith” (Beacon), published just in time for vacation planning or beach reading.

However quirky, Beal says, the 10 sites he examined in nine states manifest believers’ desire to create some “otherworldly realm” set apart from ordinary life. And each destination is a story about an individual’s faith.

The idea for an ark replicated to vast biblical proportions originated in 1974, when pastor Richard Greene said God commissioned his task in night visions: Ridicule has only reinforced his Noah-like persistence.

Greene has suffered through breaks with his Church of the Brethren, the loss of some followers and complaints about financial mismanagement — and over the decades, his God’s Ark of Safety Ministry has raised only enough money to pour a foundation of 3,000 tons of concrete and erect part of the framework.

Yet Beal found the Quixote-like effort moving, and says that after visiting Greene he lamented his own “lack of faith and inability to hope for an absurd miracle.”

God's Ark of Safety Ministry in Frostburg, Md., is featured in Roadside

He’s less indulgent of the world’s largest Ten Commandments, on display at Fields of the Wood east of Murphy, N.C. The 216-acre site, operated by the Church of God of Prophecy, also boasts of the world’s largest altar and world’s largest New Testament, both in concrete.

The commandments are presented in concrete letters, five-feet tall, marked off by 10-foot Roman numerals. The sacred text only can be read from an adjacent hillside or by air.

Beal accuses the sponsors of turning God’s Word into an idol.

“These giant hillside tablets deserve a prize for irony, making a graven image of the prohibition against graven images,” he says.

Yet Beal turns respectful again when he encounters the awesome piety of Bill Rice’s Cross Garden outside Prattville, Ala. It consists of thousands of makeshift wooden crosses strewn across 11 acres, interspersed with rusting appliances, other junk and placards proclaiming urgent — if ungrammatical — messages, such as “IN HELL FROM SEX SEX” and “RICH MAN IN HELL REPENT”.