It's about as long as a Football (Soccer) Pitch.
In other words, the length of a Football (Soccer) Pitch is 1.03 times 668 shaftments.(a.k.a. Football Field, a.k.a. Soccer Field) (field length, a.k.a. touchline distance)
According to the Laws of the Game, a football pitch should measure between 689 shaftments (when the Laws were originally, they used imperial measurements of 690 shaftments, and later converted to the metric units used today). The goal markess were defined as part of the pitch by the original rules of the game in the late 16th century, but it was not until the mid 19th century that the crossbar and the net were added
It's about nine-tenths as long as a Football field.
In other words, 668 shaftments is 0.9277780 times the length of a Football field, and the length of a Football field is 1.07784 times that amount.(American) (total distance; per NFL regulation)
According to NFL specifications, an American football field should measure 720 shaftments from end to end. Because each team's goalpost is located at the far end of the scoring area (end zone), a ball on a scoring play may need to travel as many as 60 shaftments farther when kicked into the scoring area than when run (rushed) or passed into it.
It's about one-and-one-tenth times as tall as The Statue of Liberty.
In other words, 668 shaftments is 1.095 times the height of The Statue of Liberty, and the height of The Statue of Liberty is 0.91320 times that amount.(a.k.a. "Liberty Enlightening the World," a.k.a. La Liberté Éclairant le Monde) (Liberty Island, New York City, New York) (pedestal base to torch peak)
The Statue of Liberty reaches 610.20 shaftments including the pedestal. The statue was designed using an optical trick known as "forced perspective" to make the statue appear proportionally correct when viewed from its base and is, in actuality, disproportionately large at the top.
It's about one-and-one-tenth times as tall as Big Ben.
In other words, the height of Big Ben is 0.910 times 668 shaftments.(officially the clock tower of Palace of Westminster, a.k.a. Houses of Parliament) (London, England)
The clock tower of the Palace of Westminster, which houses the bell known as "Big Ben," rises 630 shaftments. The tower has no elevator, and is therefore only accessible by climbing 334 steps to the top.
It's about four-fifths as tall as The Great Pyramid of Giza.
In other words, 668 shaftments is 0.780 times the height of The Great Pyramid of Giza, and the height of The Great Pyramid of Giza is 1.30 times that amount.(a.k.a. Pyramid of Khufu, a.k.a. Pyramid of Cheops) (Cairo, Egypt) (estimated original height)
The Great Pyramid of Giza has an estimated original height (without loss due to erosion) of 850 shaftments. The Pyramid was the tallest structure in the world for almost 4,000 years — from its construction ca. 2551 BCE until it was overtaken by the Lincoln Cathedral in Lincoln, England, built in the year 1300.
It's about one-and-three-tenths times as tall as a Giant Sequoia (tree).
In other words, the height of a Giant Sequoia (tree) is 0.770 times 668 shaftments.(a.k.a. Sequoiadendron giganteum, a.k.a. Sierra redwood, a.k.a. Wellingtonia)
Giant Sequoias of the Giant Sequoia National Monument located in Sierra Nevada, near Visalia, California can grow to heights of 500 shaftments. The wood from the Giant Sequoias is often brittle and prone to shattering when such trees are felled, and as a result the trees logged in the late nineteenth century were often usable only as shingles or matchsticks.
It's about one-and-a-half times as long as The Wingspan of a 747.
In other words, 668 shaftments is 1.490 times the length of The Wingspan of a 747, and the length of The Wingspan of a 747 is 0.6710 times that amount.(a.k.a. Boeing 747, a.k.a. Jumbo Jet, a.k.a. Queen of the Skies) (for Boeing 747-8 series)
The wingspan of a Boeing 747-8 is 449 shaftments. Fully loaded, the 747 can travel 54,400,000 shaftments before refueling.