This landmark estate represents a rare opportunity to own a founding piece of Glen Ellen, one of Sonoma Valley's most storied communities. Built in 1880 on the original land holdings that gave Glen Ellen its name, this estate traces its roots to Rancho Agua Caliente, a 3,200 acre Mexican land grant dating to 1840 that encompassed present-day Glen Ellen, Fetters Hot Springs, and Agua Caliente. In 1859, Colonel Charles V. Stuart purchased a significant portion of this land and established a 1,000-acre ranch he named Glen Ellen after his wife, Ellen, and the village that grew around the ranch adopted its name from this estate. Stuart later renamed the ranch Glen Oaks in the 1870s, but the town's identity had been written into the land. The 1880 construction places this home at the height of Glen Ellen's transformation into a premier summer retreat for San Franciscan's. The arrival of the railroad made the valley accessible, and a wave of hotels, boarding houses, and private inns opened to serve visitors seeking respite from the city. This property operated as a charming boarding house during this golden era, welcoming guests for extended stays among the vineyards and oak-studded hills. Documented establishments from this period include the Mervyn Hotel (1885), Dr. C.C. O'Donnell's health resort (1891), and the Chauvet Hotel (1906). At over 5,000 square feet across three stories, the residence offers 5 bedrooms, 5.5 bathrooms, and 11 rooms including a formal dining room. A comprehensive renovation in 1990 preserved the home's historic character while modernizing its systems for contemporary living. The property features a pool, detached storage and sits on over 22 acres of Sonoma Valley landscape. The current owners represent the third generation of families to steward this property, and their stories of its past add a layer of provenance that cannot be manufactured. Additional highlights include potential eligibility for historic designation under California's Mills Act (20-70% property tax reduction), Rural Residential-1 zoning, Sonoma Valley School District, and proximity to Glen Ellen village, Jack London State Historic Park and the wineries of Sonoma Valley.