The Brandywine Valley is home to some of the most stunning private pied-a-terre gardens to grand estate landscapes on the east coast, and many residents open their doors and their garden gates to welcome visitors on Wilmington Garden Day, an annual tradition in the area for more than 70 years. It’s a self-guided tour that you can fit into any schedule, whether you want to spend the day going from home to home or stop in at a few between other attractions.