There’s a good chance that many first-time visitors to the Trevi Fountain in Rome know the drill. To ensure a return to the Eternal City, the legend goes, stand with your back to the water and toss a coin with your right hand over your left shoulder.

The ritual became famous around the world thanks to the 1954 film “Three Coins in the Fountain,” and its eponymous song — recorded by Frank Sinatra — which won the Oscar for best original song.

The coin throw is such a popular item on tourist itineraries that even a recent three-month restoration that cut off direct access to the 18th-century fountain was not a deterrent. Visitors still crowded in front of the transparent panels protecting the work site to lob coins — about 61,000 euros’ worth, or $63,000 — into a squat utilitarian tub.

“The tourist is going to toss a coin, they don’t care about construction or no construction,” Fabrizio Marchioni said on a chilly December morning a few days before the fountain’s reopening.

He should know.

For 13 years, Mr. Marchioni’s principal job for the Roman Catholic charity Caritas has been to collect and count the coins tossed into the fountain.