Altadena is an unincorporated census-designated place in Los Angeles County, California, set along the southern foothills of the San Gabriel Mountains directly north of Pasadena and roughly 14 miles from downtown Los Angeles. The community grew in the late nineteenth and early twentieth centuries as a residential outgrowth of Pasadena, and it has long been valued for its mountain views, canyon access, and tree-lined streets. With a population of roughly 42,000, Altadena retains a semi-rural, small-town feel that sets it apart from the urban density below it. Because it is unincorporated, many services are provided by Los Angeles County, while its public schools belong to the Pasadena Unified School District. The housing stock spans more than a century of building, from early estates and Craftsman bungalows to Tudor, Mission Revival, and Mid-Century Modern designs. The community's identity is closely tied to the outdoors. Eaton Canyon Natural Area marks the northern edge, offering a nature center, trails, and the popular Eaton Falls hike, while the Altadena Crest Trail and Angeles National Forest extend the hiking network into the mountains above. Lake Avenue functions as Altadena's commercial spine, lined with long-running local restaurants, markets, and neighborhood institutions that have served residents for generations. Altadena's character is shaped by its position at the edge of the city. Streets rise toward the San Gabriels, and many homes sit within minutes of trailheads and picnic areas. The result is a place that feels removed from the pace of Los Angeles yet remains firmly connected to it. The 210 freeway and nearby Metro A Line (formerly the Gold Line) stations link residents to Pasadena, Glendale, and the broader region, making Altadena a foothill alternative for those who want canyon access and historic homes within commuting distance of the city. Because it is not an incorporated municipality, residents rely on Los Angeles County for many services, a distinction that has also helped preserve its unhurried, semi-rural character.