8 a.m., QuakerMan Triathlon, Lake Nockamixon State Park, Quakertown. QuakerMan begins with a lake swim, which is followed by a bicycle course on the rolling terrain surrounding the park. The triathlon finishes with a challenging run through the park along bike paths and back roads. Visit www.genesisadventures.com for more information.
9 a.m. to 2 p.m., Lehigh Growers Market, Landis Street and Route 309, Coopersburg
12 p.m., "Hunt for History: Magnificent Marbleizing," Spring House, Colonial Industrial Quarter, Downtown Historic Bethlehem. FREE for children with paid adult admission of $7 (limit of two children per $7). For more information, call 1-800-360-TOUR.