John M. Hay, who served as private secretary to Abraham Lincoln, built the Fells on Lake Sunapee as a summer home in 1890. House tours offer a glimpse of early-20th-century life on a New Hampshire estate. The grounds are a gardener's delight and include a 100-foot-long perennial garden and a rock garden with a brook flowing through it. Miles of hiking trails can also be accessed from the estate. The 40-minute guided house and garden tours cost an additional $6.