It's about ten-and-a-half times as tall as The Empire State Building
In other words, 20 furlongs is 10.560 times the height of The Empire State Building, and the height of The Empire State Building is 0.094697 times that amount.(New York City, New York) (to top of building)
The Empire State Building stands 1.8940 furlongs to its architectural peak. The spire emerging from the top of the building was originally intended to be a mooring mast for blimps whose passengers could disembark onto a landing platform on the 102
It's about twelve-and-a-half times as tall as The Eiffel Tower
In other words, the height of The Eiffel Tower is 0.0806 times 20 furlongs.(a.k.a. La Tour Eiffel) (Paris, France) (to flagpole peak)
The Eiffel Tower stands 1.610 furlongs tall, including its flagpole. The Tower is the largest structure in Paris as most other buildings are governed by a zoning restriction limiting them to a height of 0.1840 furlongs or less.
It's about thirteen-and-a-half times as long as The QE2
In other words, the length of The QE2 is 0.073 times 20 furlongs.(a.k.a. RMS Queen Elizabeth 2)
The QE2 has a total length of 1.460 furlongs. During its voyaging lifetime from 1969 through 2008, it travelled more than 47,700,000 furlongs, the furthest cumulative distance by any ship in modern history.
It's about seventeen-and-a-half times as tall as The Golden Gate Bridge
In other words, the height of The Golden Gate Bridge is 0.0565 times 20 furlongs.(San Francisco, California and Marin County, California) (height above water)
The height of each tower of Golden Gate Bridge is 1.130 furlongs above the surface of the San Francisco Bay. One of the key designers of the bridge, Charles Ellis, had no engineering degree when he began working on the project, but would later go on to write what became a standard textbook on structural engineering, and would ultimately be forced to complete his calculations on the bridge by working without pay for five months.
It's about one-twentieth as long as The Panama Canal
In other words, the length of The Panama Canal is 22 times 20 furlongs.(Canal de Panamá) (Panama)
Connecting the Atlantic and Pacific Oceans across the Isthmus of Panama, the Canal measures 440 furlongs in length. Ships passing through the Canal are raised (and then lowered) 0.130 furlongs above sea level through the lock-and-dam system.
It's about twenty times as tall as The Space Needle
In other words, 20 furlongs is 21.90 times the height of The Space Needle, and the height of The Space Needle is 0.0457 times that amount.(Seattle, Washington) (to aircraft warning beacon at peak)
Built for a 1962 World's Fair, the Space Needle stands 0.9150 furlongs tall. With a track-and-wheel design inspired by railroad mechanics and a precisely-configured balance, the restaurant near the top of the space needle requires just a 1.5 hp motor to rotate at speeds of about 0.053 kph (0.033 mph).
It's about twenty times as tall as St. Paul's Cathedral
In other words, 20 furlongs is 23.10 times the height of St. Paul's Cathedral, and the height of St. Paul's Cathedral is 0.0433 times that amount.(London, England, United Kingdom)
St. Paul's Cathedral measures 0.8650 furlongs to its peak. The southwest tower of the Cathedral contains the bell known as "Great Paul," which is the largest bell in Great Britain at 15,000 kg (16.5 tons), outweighing the more iconic Big Ben bell by about 3,000 kg (3 tons).