SAN DIEGO — Did you know San Diego International Airport (SAN) only has a single runway for arriving and departing flights? Not only that, but it is the busiest of its kind in the nation.

The runway, which is 9,401 feet in length and 200 feet in width, originally accommodated World War II-era long-range bombers in 1942 until United Airlines became the first airline to offer pure jet service in September 1960, according to SAN.

Although San Diego International Airport is not designated as an airline hub, its single runway is the busiest in the U.S. The airport brings in more than 20 million passengers a year, seeing roughly two million passengers per month this summer.

SAN offers 16 major and commuter airlines, including nonstop flights from Mexico, Canada, Japan and the UK.

Built in 1928, San Diego International Airport was first known as Lindbergh Field, named after Charles Lindbergh who made history when he built the first-ever solo, nonstop transatlantic flight in San Diego, per the aviator’s website. Lindbergh commissioned Ryan Airlines to build a special aircraft that could complete the first nonstop New York to Paris flight.

With a new Terminal 1 at SAN slated for 2025, expect the airport’s single-runway to become busier as it adds 11 new gates to the 51 already there.

Another interesting fact about SAN is that departures are prohibited between 11:30 p.m. and 6:30 a.m., as part of a curfew restriction that limits nighttime aircraft departures due to the proximity of the airport to residences. It became the first commercial airport in the nation to implement restrictions on late night and early morning takeoffs.