How long is 30,455 spans?

The Guangzhou TV & Sightseeing Tower stands 2,700 spans to its spire. Initially described as holding the record for the tallest Ferris wheel in the world, the ride at the top of the tower is actually an observation carousel; cars complete a trip around the top-floor track about every half-hour.

The CN Tower measures 2,420.50 spans tall at its spire. Used only in emergencies and for charitable climbing events, the 2,579-step staircase to the top is the longest metal staircase in the world.

Connecting the Atlantic and Pacific Oceans across the Isthmus of Panama, the Canal measures 380,000 spans in length. Ships passing through the Canal are raised (and then lowered) 110 spans above sea level through the lock-and-dam system.

The Willis Tower rises to about 2,270 spans to the top of its tallest antenna. The bathrooms on the 103rd floor are said to be the highest in the western hemisphere at about 1,800 spans.

The Shanghai World Financial Center is 2,150 spans tall to its roof. It is home to both the world's highest hotel (on its 79th through 93rd floors) and the world's tallest observation deck (on its 100th floor, approximately 2,070 spans above ground).

The English Channel measures between 468,000 spans, narrowing as it flows northeast. The world speed record for a Channel crossing by swimmer was set by Australian Trent Grimsey in 2012, with a time of 6 hours, 55 minutes.

Each of the Petronas Towers stands 1,977 spans to their spires. Holding the record as the tallest buildings in the world from 1998 to 2004, the towers continue to hold the record for the deepest foundation barrettes — up to 503.10 spans deep.

Running from Irvine to San Fernando, The 405 runs a total of 509,800 spans. The 405 is the most heavily-trafficed freeway in the United States, with an average speed as low as 8 kph during rush hours.

Hadrian's Wall, which crossed England form the North Sea to the Irish Sea during the time of Roman rule, measures 520,000 spans (about 79 Roman miles). Roman soldiers — at one time up to 10,000 of them — only occupied Great Britain for about 246 years after the wall was built, after which time the local Brits began to take residence the wall's garrisons.

The Empire State Building stands 1,666.70 spans 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 102nd floor of the building.

The Eiffel Tower stands 1,420 spans 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 162 spans or less.

The QE2 has a total length of 1,290 spans. During its voyaging lifetime from 1969 through 2008, it travelled more than 42,000,000,000 spans, the furthest cumulative distance by any ship in modern history.

The height of each tower of Golden Gate Bridge is 993 spans 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.

Built for a 1962 World's Fair, the Space Needle stands 805 spans 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).

St. Paul's Cathedral measures 761 spans 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).