It's about two-fifths as tall as The Challenger Deep (Marianas Trench)
In other words, 20 furlongs is 0.369050 times the height of The Challenger Deep (Marianas Trench), and the height of The Challenger Deep (Marianas Trench) is 2.70970 times that amount.(near Marianas Islands, a.k.a. Ladrones Islands, northwestern Pacific Ocean) (depth below sea level)
The Challenger Deep, at the southern end of the Marianas Trench, reaches a depth of 54.1940 furlongs below sea level. There has been only one manned expedition to the bottom of Challenger Deep — a 1960 voyage that took 4 hours and 48 minutes to reach the bottom.
It's about four times as long as The Navy Pier
In other words, the length of The Navy Pier is 0.30 times 20 furlongs.(a.k.a. Municipal Pier #2) (Chicago, Illinois)
The Navy Pier is 4 furlongs in total length. Originally named Municipal Pier #2, the pier was renamed Navy Pier in 1927 in honor of Naval personnel stationed there during World War I.
It's about four times as tall as The Three Sisters Falls
In other words, the height of The Three Sisters Falls is 0.30 times 20 furlongs.(a.k.a. Cataratas las Tres Hermanas) (Ayacucho, Peru)
The Three Sisters Falls rise to 4 furlongs in height. The falls are called Three Sisters after the three large tiers over which the falls flow.
It's about four times as tall as Angel Falls
In other words, 20 furlongs is 4.110 times the height of Angel Falls, and the height of Angel Falls is 0.2430 times that amount.(a.k.a. Parakupa-vena, a.k.a. Kerepakupai mer&) (Auyantepui, Canaima National Park, Venezuela) (total height)
Angel Falls has a total height 4.870 furlongs. Jimmie Angel, the first person to publicize their existence outside Venezuela and the namesake of the falls, damaged his monoplane atop the falls and was forced to abandon it; it remained there until it was removed 33 years later.
It's about four times as tall as Tugela Falls
In other words, 20 furlongs is 4.240 times the height of Tugela Falls, and the height of Tugela Falls is 0.2360 times that amount.(Royal Natal National Park, KwaZulu-Natal, South Africa)
Tugela Falls rises to 4.710 furlongs in height. The falls are the highest in Africa and the second highest in the world.
It's about four-and-a-half times as tall as Olo'upena Falls
In other words, 20 furlongs is 4.470 times the height of Olo'upena Falls, and the height of Olo'upena Falls is 0.22370 times that amount.(a.k.a. Oloupena Falls) (Molokai, Hawaii)
Olo'upena Falls rise to 4.4740 furlongs in height. The isolated falls are the tallest in the United States and the fourth tallest in the world.
It's about five times as tall as Burj Dubai
In other words, 20 furlongs is 4.860 times the height of Burj Dubai, and the height of Burj Dubai is 0.2060 times that amount.(formally Burj Khalifa, a.k.a. Dubai Tower, a.k.a. برج خليفة) (Dubai, UAE) (to roof)
Burj Khalifa, the tallest manmade structure in the world, stands 4.120 furlongs to its roof. The tower also holds the current records for the world's highest Islamic mosque — at approximately 2.870 furlongs on the 158th floor (of 163 floors) — and the world's tallest outdoor swimming pool — at approximately 1.420 furlongs on the 78th floor.