ST. HELENA. From the 1840s until the early 20th century, this grist mill was the center of social activity in Napa Valley, and settlers in the vicinity would gather to discuss pertinent events and oversee the grinding of wheat and corn. The mill's foundation was constructed entirely of native stone, and sturdy Douglas firs and redwoods were used in the walls and ceilings of both the mill and granary. Today, the mill and its 30-foot-plus waterwheel are protected by the state, as are a nearby pioneer cemetery and church, the first church built in Napa Valley.

NAPA. For gastronomes and wine connoisseurs, a visit to this Napa Valley treasure is a must. COPIA's contemporary stone exterior is surrounded by expertly manicured gardens and flowerbeds. Within the center, which offers a museum in addition to its wide range of educational resources, visitors can explore America's contributions to the culinary arts. Be sure to browse Cornucopia, the museum store, to find unique gifts and participate in a wine tasting at the Wine Spectator Tasting Table. The well-reviewed Julia's Kitchen is ideal for diners wanting to enhance their visit with gourmet cuisine.

JENNER. Situated on a bluff overlooking the Sonoma coast, Fort Ross State Park includes 90-some acres of meadows, tidal areas, and submerged land. The fort, established by the Russians in 1812, originally served as an outpost for sea otter hunters and was bought by John Sutter, who owned the Sierra Nevada sawmill where gold was discovered in the 1840s. Although the fort no longer contains any original buildings, its reconstructions are near-matches, as the Orthodox chapel and commons buildings prove.

SANTA ROSA. Luther Burbank, one of America's leading 19th-century horticulturists, lived in and worked on this parcel of land for many decades. On the property, he experimented with a few of the more than 800 varieties of plants that he developed over the course of his career. A contemporary of Thomas Edison and Henry Ford, Burbank often received both men as guests at his downtown home. Today, the acre of gardens features a cutting garden, medicinal plants, roses, and more. The greenhouse, constructed in 1889, features rotating exhibits and a replica of Burbank's office; the carriage house, renovated as a museum, preserves a variety of Burbank's personal effects. It also boasts a gift shop.

SONOMA. The original heart and soul of downtown Sonoma, Mission San Francisco Solano was founded in July of 1823 by Padre Jose Altimira. San Francisco Solano was named after a Peruvian missionary and was the 21st mission constructed in Alta California. It remained in operation until 1834, when it was designated a parish by the Mexican Congress. Featuring classic Spanish Mission-style architecture accented by lovely flowerbeds, the structure is now part of the Sonoma State Historic Park. Admission is $2 and includes all buildings within the park.