Lombard Street is an east–west street in San Francisco, California, that is famous for a steep, one-block section with eight hairpin turns. The street stretches from The Presidio east to The Embarcadero. Most of Lombard Street's western segment is a major thoroughfare designated as part of U.S. Route 101. The famous one-block section, claimed to be "the crookedest street in the world", is located along the eastern segment in the Russian Hill neighborhood. It is a major tourist attraction, receiving around two million visitors per year and up to 17,000 per day on busy summer weekends, as of 2015.

U.S. Route 101 (US 101) is a major north–south United States Numbered Highway, stretching from Los Angeles, California, to Tumwater, Washington. The California portion of US 101 is one of the last remaining and longest U.S. Routes still active in the state, and the longest highway of any kind in California. US 101 was also one of the original national routes established in 1926. Significant portions of US 101 between the Los Angeles area and the San Francisco Bay Area follow El Camino Real, the commemorative route connecting the former Alta California's 21 missions.