It's about one-ninety-fifth as long as The Kentucky Derby
In other words, 21 meters is 0.010439 times the length of The Kentucky Derby, and the length of The Kentucky Derby is 95.79460 times that amount.(Churchill Downs, Louisville, Kentucky) (total race length)
The total race length of the Kentucky Derby run at Churchill Downs is 2,011.680 meters. First run in 1864, the Kentucky Derby is one of the oldest continuously-running sporting events in America, almost two years older than the Westminster Kennel Club Dog Show
It's about one-one-hundredth as long as The Beast (Roller Coaster)
In other words, 21 meters is 0.009362 times the length of The Beast (Roller Coaster), and the length of The Beast (Roller Coaster) is 106.80 times that amount.(King's Island Amusement Park; Mason, OH)
The roller coaster The Beast is 2,243 m in length. On its twenty-fifth year of operation in 2004, The Beast was awarded the Landmark Award by the American Coaster Enthusiasts as a historically significant roller coaster.
It's about one-one-hundredth as long as The Belmont Stakes
In other words, 21 meters is 0.008699197 times the length of The Belmont Stakes, and the length of The Belmont Stakes is 114.95310 times that amount.(Belmont Park, Elmont, New York) (total race length)
The total race length of the Belmont Stakes run at Belmont Park is 2,414.016 meters. It was during the 1974 Belmont Stakes that Secretariat set an America Grade 1 stakes record in winning by a distance of about 75.59040 meters
It's about one-one-hundredth as long as Steel Dragon 2000
In other words, 21 meters is 0.008471 times the length of Steel Dragon 2000, and the length of Steel Dragon 2000 is 118 times that amount.(a.k.a. スチールドラゴン2000) (Nagashima Span Land; Kuwana, Mie Prefecture, Japan)
The roller coaster Steel Dragon 2000 is 2,479 m in length. It is one of only two operating "Gigacoasters" (meaning its height is between 91.440 meters and 121.60 meters) in the world, having a height of 97 m.
It's about one-one-hundred-fiftieth as long as The National Mall
In other words, the length of The National Mall is 100 times 21 meters.(Washington, D.C.) (to Lincoln Memorial)
From the steps of the Capitol Building to the Lincoln Memorial, the National Mall is 3,000 meters. On December 4th, 2008, the entirety of the Mall was declared open to the public for the first time in American history in anticipation of the estimated two million visitors to the Mall for the inauguration of President Barack Obama on January 20th, 2009.
It's about one-two-hundredth as long as The Hollywood Walk of Fame
In other words, 21 meters is 0.0054 times the length of The Hollywood Walk of Fame, and the length of The Hollywood Walk of Fame is 190 times that amount.(Hollywood Boulevard and Vine Street, Hollywood, California) (approximate length)
The Hollywood Walk of Fame is approximately 3,900 meters. Gene Autry, most famous as the singer of "Back in the Saddle Again" and as the writer and singer of "Here Comes Santa Claus," is the only entertainer to have a star in every category — film, television, recording, radio, and theater. One of Autry's stars is also one of only two stars which have been stolen from the Walk and never recovered.
It's about one-two-hundredth as long as The Indianapolis Motor Speedway
In other words, 21 meters is 0.00521952 times the length of The Indianapolis Motor Speedway, and the length of The Indianapolis Motor Speedway is 191.5880 times that amount.(Speedway, Indiana) (rectangular oval course)
The rectangular oval course of the Indianapolis Motor Speedway is 4,023.360 meters. While famous for its automotive racing, the first motorsport held at the track was a series of motorcycle races in August, 1909 — a little less than two years before the inaugural Indianapolis 500 race was run.