In these days of family-friendly splish-splashing and resorts luring gen-blend groups with water parks as bait, it’s sometimes forgotten that the Poconos weren’t always a kid-forward destination.

As of Sunday, Dec. 18, a resort in Mount Pocono will be for adults only. Mount Airy Casino Resort in Mount Pocono, Monroe County, has announced that all guests on the entire property must be at least ...