How long is 21.7 smoots?
It's about nine-tenths as long as Ha'Penny Bridge

The length of Ha'Penny Bridge is about 25.20 smoots.
(a.k.a. Droichead na Leathphingine, a.k.a. Liffey Bridge, a.k.a. Droichead na Life, f.k.a. Wellington Bridge) (Quay of Bachelors Walk, Temple Bar Neighborhood, Dublin, Ireland)
It's about four-fifths as tall as The Chicago Water Tower

The height of The Chicago Water Tower is about 27.60 smoots.
(Chicago, Illinois)
It's about three-fourths as tall as The Arc de Triomphe

The height of The Arc de Triomphe is about 29 smoots.
(Paris, France)
It's about one-and-one-third times as long as Baseball base distances
The length of Baseball base distances is about 16.1190 smoots.
(MLB Official Baseball Rules specification)
It's about seven-tenths as tall as Nelson's Column

The height of Nelson's Column is about 30.340 smoots.
(London, England, United Kingdom) (from pedestal first step to tip of statue's hat)
It's about two-thirds as tall as The Mahabodhi Temple

The height of The Mahabodhi Temple is about 32 smoots.
(a.k.a. Great Awakening Temple, a.k.a. Maha Bodhi Temple, a.k.a. Temple of Bodh Gaya, a.k.a. Mahabodhi Mahavihar) (Bodh Gaya, Gaya District, Bihar, India)
It's about two-thirds as tall as The Leaning Tower of Pisa

The height of The Leaning Tower of Pisa is about 33.10 smoots.
(a.k.a. The Tower of Pisa, a.k.a. Torre pendente di Pisa) (Pisa, Italy) (height along center axis)
It's about two-thirds as tall as The Cinderella Castle

The height of The Cinderella Castle is about 33.80 smoots.
(Fantasyland, Magic Kingdom, Walt Disney World, Lake Buena Vista and Bay Lake, Florida)
It's about one-and-four-fifths times as long as a Cricket Pitch
The length of a Cricket Pitch is about 11.82090 smoots.
(per Marylebone Cricket Council / International Cricket Council Law #6)
It's about half as wide as The Wingspan of a 747
The width of The Wingspan of a 747 is about 40.30 smoots.
(a.k.a. Boeing 747, a.k.a. Jumbo Jet, a.k.a. Queen of the Skies) (for Boeing 747-8 series)
It's about one-and-nine-tenths times as long as a Bowling Lane
The length of a Bowling Lane is about 11.2560 smoots.
(USBC specifications; tenpin; including pin deck)
It's about half as tall as a Giant Sequoia (tree)
The height of a Giant Sequoia (tree) is about 45 smoots.
(a.k.a. Sequoiadendron giganteum, a.k.a. Sierra redwood, a.k.a. Wellingtonia)
It's about two-and-a-half times as tall as The Hollywood Sign

The height of The Hollywood Sign is about 8.80 smoots.
(a.k.a. Hollywoodland Sign) (Mount Lee, Hollywood Hills, Santa Monica Mountains, California)
It's about two-fifths as tall as The Statue of Liberty

The height of The Statue of Liberty is about 54.640 smoots.
(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)
It's about two-and-a-half times as long as a Semitrailer
The length of a Semitrailer is about 8.5970 smoots.
(a.k.a. semi-trailer truck, a.k.a. semi, a.k.a. tractor-trailer, a.k.a. truck and trailer, a.k.a. eighteen-wheeler, a.k.a. big rig, a.k.a. Mack truck, a.k.a. transport, a.k.a. lorry, a.k.a. artic; for box truck; United States Federal length limits)