DUBLIN —If you ever visit Dublin, don’t be alarmed by the sound of smashing steel erupting from the bustling roads here. In this fair city, the clanging is just a flatbed truck absorbing the bounces off concrete as it hauls dozens of kegs of Guinness around town.

The locals were unbothered by the familiar racket. But as the truck rounded a corner at St. Patrick’s Cathedral, it caused hundreds of American tourists in purple and white and cardinal and gold to turn their heads and furrow their brows. The visitors in American football jerseys and T-shirts stood on hallowed grounds where, 1,500 years ago, Saint Patrick first baptized Christian converts.

Tour groups went back to listening about the church built in 1191. One shaggy-haired young visitor lagged behind as he twirled a football.

A foreign object to many in this city, but for how long?

For the fourth straight year, college football kicked off another season from its quaint vacation home on the east coast of the Emerald Isle. Kansas State and Iowa State brought 22,000 fans to Ireland for the premier Week 0 matchup of AP Top 25-ranked teams in the Aer Lingus College Football Classic. The NFL will come to town in September for its first-ever regular-season game on Irish soil.