California State Route 110, also known as the Pasadena Freeway, is a major highway in Southern California. It runs approximately 27 miles from Los Angeles to Pasadena, connecting several key neighborhoods and providing access to various attractions. The route is notable for being one of the oldest freeways in the United States, originally opened in 1940. It features several interchanges and connects with other major roads, including Interstate 5 and Interstate 10, facilitating travel throughout the region.