It's about one-and-one-tenth times as tall as Nelson's Column
In other words, 521 hands is 1.03 times the height of Nelson's Column, and the height of Nelson's Column is 0.9756 times that amount.(London, England, United Kingdom) (from pedestal first step to tip of statue's hat)
Nelson's Column measures 508.30 hands from the first step of the pedestal's base to the top of the statue's hat. While the London tower is the tallest, there are at least eight other monuments to Admiral Horatio Nelson, 1st Viscount Nelson, 1st Duke of Bronté throughout England, Scotland, Ireland, Canada, and Barbados.
It's about as tall as The Mahabodhi Temple
In other words, 521 hands is 0.96 times the height of The Mahabodhi Temple, and the height of The Mahabodhi Temple is 1 times that amount.(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)
The tower of the Mahabodhi Temple measures 540 hands in total height. The site has been of sacred interest for more than 2,000 years, with the current Temple dating back at least 1,400 years.
It's about nine-tenths as tall as The Leaning Tower of Pisa
In other words, 521 hands is 0.939 times the height of The Leaning Tower of Pisa, and the height of The Leaning Tower of Pisa is 1.1 times that amount.(a.k.a. The Tower of Pisa, a.k.a. Torre pendente di Pisa) (Pisa, Italy) (height along center axis)
The Leaning Tower of Pisa stands 555 hands tall along the angle of its lean. In May of 2008, in an successful effort to stabilize the tower, 70 tonnes of earth were removed from the tower's base on the side opposite the lean.
It's about nine-tenths as tall as The Cinderella Castle
In other words, 521 hands is 0.919 times the height of The Cinderella Castle, and the height of The Cinderella Castle is 1.1 times that amount.(Fantasyland, Magic Kingdom, Walt Disney World, Lake Buena Vista and Bay Lake, Florida)
Walt Disney World's Cinderella Castle is 567 hands tall. The castle's architecture uses the optical trick known as "forced perspective" — the castle gets smaller near the top — to appear larger than it truly is.
It's about one-and-one-tenth times as tall as The Arc de Triomphe
In other words, 521 hands is 1.1 times the height of The Arc de Triomphe, and the height of The Arc de Triomphe is 0.91 times that amount.(Paris, France)
The Arc de Triomphe stands 480 hands tall. France's Tomb of the Unknown Soldier from the First World War lies beneath the arch and is commemorated by the first eternal flame to have been lit in modern European history.
It's about one-and-one-tenth times as tall as The Chicago Water Tower
In other words, 521 hands is 1.13 times the height of The Chicago Water Tower, and the height of The Chicago Water Tower is 0.885 times that amount.(Chicago, Illinois)
The Chicago Water Tower is 462 hands tall. The tower's architecture was one source of inspiration behind the design of White Castle fast-food restaurants beginning with "Building Number 8," a prefabricated structure built in Minneapolis, Minnesota in 1936.
It's about one-and-one-fourth times as long as Ha'Penny Bridge
In other words, 521 hands is 1.23 times the length of Ha'Penny Bridge, and the length of Ha'Penny Bridge is 0.813 times that amount.(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)
The Ha'Penny Bridge, crossing the River Liffey in Dublin, measures 422 hands in total length. Over 30,000 pedestrians cross the breach each day.