Enjoy displays of seasonal decorations and lights in the Mansion and Sonnenberg grounds, including activities and musical performers! A perfect way to celebrate the holiday season in the Finger Lakes. One of the most treasured landmarks of our region, Sonnenberg Gardens, greets 35,000 visitors annually and has been doing so since it opened its doors to the public in 1973. Visitors from all over the globe come to enjoy the relaxing nature and beauty of its gardens. Many also come to learn about the history of this unique place and its original owners, Frederick and Mary Clark Thompson.