On Christmas Day, an artwork that has been at the center of one of the year’s greatest art mysteries will go on the auction block. It’s the capstone to a saga that has gripped a nation. A mural based ...

Forget the monoliths—there’s a new monument perplexing America. An artist was commissioned by a local business owner to create a mural of Sesame Street’s Cookie Monster on the side of his building.

An unassuming Illinois city has become the site of a captivating art mystery. And this one has nothing to do with monoliths. At the center of the drama is the question of who paid local artist Joshua ...