The biannual event, a benefit for the South Orange Historical and Preservation Society, provides curious neighbors as well as architecture buffs from the region an indoor/outdoor exploration of residences that they would not ordinarily get to see. The Saturday tour, timed perfectly to coincide with the peak blooms of daffodils, tulips, hyacinths, cherry trees, and magnolias is open to the public between 11 and 4. A donation is required.