In the early 20th century, Filipinos were concentrated in Downtown San Diego, particularly around Market Street; the area was known as "skid row". In the 21st century, Filipino Americans form the largest Asian American subgroup in San Diego County, at almost 6% of the entire county population. San Diego has historically been a popular destination for Filipino immigrants, and has contributed to the growth of its population. National City, a city bordering the south boundary of San Diego, has a large concentration of Filipino residents, forming almost 17% of the population as of the 2010 Census. Other concentrations include the neighborhoods of Mira Mesa, often referred to as "Manila Mesa", Rancho Penasquitos, Paradise Hills and along Plaza Boulevard in National City. A portion of California State Route 54 in San Diego is officially named the "Filipino-American Highway", in honor of the Filipino American Community.