The Stagecoach Inn Museum in Newbury Park, California, originally known as the Grand Union Hotel, was used as a resting area for people who traveled from Los Angeles to Santa Barbara. Besides a hotel and stagecoach stop, it has also been used as a post office, church, restaurant and military school. It is California Historical Landmark No. 659 and is listed in the National Register of Historic Places. It played a major role in the development of the stage line transportation network in California. The hotel was also the first business venture in the Conejo Valley.
 Today, the inn is owned by the Conejo Recreation and Park Department and operated as a historic museum. The museum includes a rebuilt Timber School (originally built in 1889), a carriage house and blacksmith shop, nature trails, and the "Tri-Village", a small group of three houses: the pioneer house, the adobe, and the Chumash "ap". There is also a gift shop located inside the museum. A director and volunteers operate the museum, being members of the Conejo Valley Historical Society (CVHS). There is also a Jr. Docent program for children and teenagers aged 8–18. It is a dominant cultural and educational gathering place for thousands of residents and visitors to Newbury Park.
 The Stagecoach Inn Museum is allegedly haunted, and is considered one of California's most famous haunted places.
 The Stagecoach Inn Museum has had a variety of names and owners:
 James Hammell was a carpenter in Santa Barbara who planned to construct a hotel along the stagecoach route from Los Angeles to Santa Barbara. After talking to John Edwards about his plans in the late 19th century, Hammell purchased 4,200 acres of land from Edwards. Near what is now Highway 101 and Ventu Park Road is where Hammell first began constructing the hotel.  The Grand Union Hotel was constructed in 1876 and was originally planned as a stopover for travelers between Los Angeles and Santa Barbara. It was constructed using redwood brought by sea from Northern California. When it arrived in Port Hueneme, it was moved by multiteam wagons up the Conejo Grade .
 One month before the hotel's grand opening, the Coast Line Stage Company changed its route, eliminating Conejo Valley, which meant an end to Hammell's prospects of a mainline stage stop. Hammell did not cancel his plans, but instead opened the hotel in August of 1876 although planned for July 4th. It was publicized as a "health and pleasure resort". A countywide newspaper reported: "Shooting, fishing, bathing, and a first-rate table are among the good things on hand for visitors."
 Following the drought of 1877-78 James Hammell no longer owned the hotel. After passing through several owners, it was purchased in 1885 by Cecil Haigh, an Englishman. His grandson, H. Allen Hays gave the building and about four acres of land at the present location to the CVHS, who later deeded the property to the Conejo Recreation and Park District in return for a 50-year renewable lease to operate the facilities for cultural and educational purposes. In the 1960s, the hotel was threatened with demolition by the expansion of the Ventura Freeway, but it was granted Historical Landmark status and moved to its present location in 1966.  On April 25, 1970, a fire destroyed the museum and its contents. The reconstructed museum was dedicated and opened on July 4, 1976; the second floor was not completed until 1980.  The structure was rebuilt using the original Monterey-style architecture.
 The Stagecoach Inn Museum was designated Ventura County Historic Landmark No. 30 in 1976 and designated California Historical Landmark No. 659 and also placed on the U.S. National Register of Historic Places in 1975. It is City of Thousand Oaks Historical Landmark No. 1.
 Also on the museum grounds is Timber School, a reproduction of the 1889 school. 
 On July 13, 2004, the Thousand Oaks City Council voted unanimously to declare the 1924 Timber School on Newbury Road City Landmark No. 12.
 On the museum grounds, near the Tri-Village Complex, is a historic 250+ year old sycamore tree. The tree was designated Ventura County Landmark No. 44 on June, 1978, due to its "great age, size, and formation." The tree is also designated Thousand Oaks City Landmark No. 2.  Furthermore, General John C. Frémont passed by this tree in 1846 on his way to sign a treaty with General Andrés Pico to secure California's annexation to the U.S. The Chumash Indians are said to have bent the lower branches to mark the location of underground water.
 The museum is home to permanent exhibits such as the Carriage House, Blacksmith Shop, Anderson Exhibit Hall, Tri-Village and Timber School. The Tri-Village represents three historic eras in the Conejo Valley: the Newbury Pioneer House, a Spanish Adobe and a reconstructed Chumash village. The exhibits are changing routinely. Temporary exhibits as of July 2018 includes Jungleland USA, vintage dresses, and fossils of the Conejo Valley.
 Minerals, shells, gramophones, irons, laundry tools and fossils have been on display here. Chumash pictographs have also been on display here.
 Stagecoach Inn Museum Park sits adjacent to the Stagecoach Inn Museum, located at the corner of Lynn and Ventu Park Roads. The park was acquired by the Conejo Recreation & Park District in 1968, and later developed into a neighborhood park in 1985. A creek runs through the park on one edge. The park has a playground, picnic tables, barbecue grills and an outdoor basketball court.
 The Rosewood Trail to the 1,603 ft. peak Angel Vista in the Santa Monica Mountains can be reached from the park. Hikers may park at the park and access the Rosewood Trail from its trailhead immediately across Lynn Road from the Stagecoach Inn Museum Park.
 The Conejo Valley Historical Society was established on October 9, 1964, as an effort to save the Stagecoach Inn from potential demolition due to expansion of the Ventura Freeway. Its members were able to save the structure and was also successful in having it declared California State Landmark No. 659. H. Allen Hays, the grandson of Cecil and Cicelie Haigh, donated the building and approximately four acres of land to the Conejo Valley Historical Society. The society deeded the site to the Conejo Recreation and Park District (CRPD) in return for a renewable lease to operate and manage the complex for cultural and educational purposes. The society helped prepare it as a museum after the 1966 move, and the society made immediate plans for rebuilding the structure after the April 1970 fire.
 The Conejo Valley Historical Society frequently holds meetings and events at the Stagecoach Inn Museum.