It's about three-fifths as tall as Aconcagua
In other words, 20 furlongs is 0.577910 times the height of Aconcagua, and the height of Aconcagua is 1.73040 times that amount.(a.k.a. Cerro Aconcagua) (Mendoza, Argentina)
Aconcagua measures 34.6070 furlongs height at its peak. Although there is no definitive evidence that members of the indigenous Inca civilization ever reached the peak the mountain, numerous archeological sites have been found on the slopes of the mountain, including a naturally-embalmed Incan mummy was discovered on a 25.8490 furlongs high ridge.
It's about one-and-four-fifths times as long as The Beast (Roller Coaster)
In other words, 20 furlongs is 1.7940 times the length of The Beast (Roller Coaster), and the length of The Beast (Roller Coaster) is 0.55740 times that amount.(King's Island Amusement Park; Mason, OH)
The roller coaster The Beast is 11.150 furlongs 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 two times as long as The Kentucky Derby
In other words, the length of The Kentucky Derby is 0.50 times 20 furlongs.(Churchill Downs, Louisville, Kentucky) (total race length)
The total race length of the Kentucky Derby run at Churchill Downs is 10 furlongs. 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 two times as long as The Preakness Stakes
In other words, 20 furlongs is 2.1052630 times the length of The Preakness Stakes, and the length of The Preakness Stakes is 0.4750 times that amount.(Pimlico Race Course, Baltimore, Maryland) (total race length)
The total race length of the Preakness Stakes run at the Pimlico Race Course is 9.5 furlongs. Dubbed "the race for the Black-eyed Susans" after Maryland's state flower, the winning horse is actually draped with a garland of painted yellow daisies, as Black-eyed Susans do not bloom in time for the late-May race.
It's about half as tall as Mount Everest
In other words, 20 furlongs is 0.4550 times the height of Mount Everest, and the height of Mount Everest is 2.20 times that amount.(a.k.a. Mount Chomolungma, a.k.a. Sagarmatha, a.k.a. Mount Qomolangma, a.k.a. सगरमाथा, a.k.a. Chajamlungma, a.k.a. ཇོ་མོ་གླང་མ, a.k.a. 珠穆朗玛峰, a.k.a. Zhūmùlǎngmǎ Fēng) (Sagarmatha Zone, Nepal and Tibet, China) (to summit, excluding snow depth)
Mount Everest is 44 furlongs above sea level at its summit. The plate tectonics of the Indian subcontinent continuously alter the mountain's peak â€” raising it by 0.00001990 furlongs and shifting it to the northeast by 0.00002240 furlongs each year.
It's about two-fifths as tall as a Mauna Loa
In other words, 20 furlongs is 0.43880 times the height of a Mauna Loa, and the height of a Mauna Loa is 2.2790 times that amount.(Hawaii) (Hawaiian island volcano) (total height from seafloor)
Mauna Loa, one of the five volcanoes which forms the island of Hawaii and the tallest mountain in total height in the world, rises to 45.730 furlongs above the seafloor. The peak of Loa is home to the approximately 6,000 sq. m (0.6 ha) Lake Waiau, one of the highest altitude lakes in the United States outside of Colorado.
It's about two-fifths as tall as Maxwell Montes
In other words, 20 furlongs is 0.370 times the height of Maxwell Montes, and the height of Maxwell Montes is 2.70 times that amount.(Ishtar Terra, Venus)
Maxwell Montes rises to a total height of 55 furlongs. Since Venus does not seem to have the kind of tectonic activity which gives rise to mountains on Earth, the origin of the Venusian mountain remains the subject of some dispute.