Teatro Juarez is the building that most clearly shows El Oro's old money. Its exterior is handsome enough, but the interior is the surprise: carved wood, gilded detail, and a theatrical Art Nouveau mood that feels almost improbable in a small mountain town.
It was built during the Porfirian mining boom, when El Oro wanted civic buildings to match its gold output. If the doors are open, go in; otherwise the theatre is still worth seeing from the plaza.