Philadelphia City Hall, once referred to by Walt Whitman as “a majestic and lovely show there in the moonlight,” has stood as an architectural wonder in the city's center since 1901. Here are 11 facts about the seat of Philadelphia’s government.

1. WILLIAM PENN LAID OUT THE BUILDING'S SPOT 200 YEARS BEFORE IT WAS BUILT.

William Penn, who founded the Province of Pennsylvania in 1681, planned the city of Philadelphia in a grid pattern between the Delaware and Schuylkill Rivers. In the center, he set aside five parcels of land for public spaces, including a “Centre Square” that was designated for public buildings—the future site of City Hall. Inside City Hall is a plaque inscribed with Penn’s “Prayer for Philadelphia” that he composed prior to departing for England.

2. CONSTRUCTION TOOK 30 YEARS AND COST NEARLY $25 MILLION.

After years of political wrangling about the location, construction began on what was to become City Hall in 1871. But completion of the project stretched into the following century, and the political machine in the city led to numerous delays and cost overruns, with the price tag eventually reaching more than $24 million. The interior of the building was finally finished in 1901.

3. IT (SORT OF) HELD THE TITLE OF WORLD'S TALLEST BUILDING FOR 14 YEARS.

The designers of City Hall, including Scottish architect John McArthur, Jr., intended for the building to be the tallest in the world upon its completion. But its long gestation period allowed the 555-foot Washington Monument (which opened in 1886, then reopened in 1888) and the 984-foot Eiffel Tower (completed in 1889) to take the title. Once a massive, 37-foot statue of Penn was erected atop City Hall in 1894, however, it reached 548 feet tall and surpassed the Ulm Münster (530 feet) in Baden-Württemberg, Germany as the tallest occupied building in the world (although it wouldn’t officially count until opening in 1901). The 612-foot tall Singer Building in Manhattan debuted in 1908 and held the title for one year.

4. IT WAS PHILLY'S TALLEST BUILDING FOR NEARLY 100 YEARS.

A long-held “gentlemen’s agreement” among city developers ensured that no building in Philadelphia would reach past the tip of Penn’s hat at 548 feet. But in 1987, the 945-foot One Liberty Place—which was spearheaded by real estate magnate Willard Rouse—opened at 17th and Market Streets to overtake City Hall atop the Philly skyline.

5. NO OTHER CITY HAS A LARGER MUNICIPAL BUILDING.

With 14.5 acres of floor space, almost 700 rooms, and offices and chambers for the city’s executive, judicial, and legislative branches, Philadelphia City Hall is the biggest municipal building in America. It is taller and has more rooms than the U.S. Capitol Building, though it has a smaller total floor space than the Capitol’s 16.5 acres.

6. IT'S THE WORLD'S TALLEST MASONRY STRUCTURE.

Constructed of brick, marble, and granite, with no steel or iron framing, City Hall is the tallest masonry building in the world and one of the largest overall. More than 88 million bricks were used in the building’s construction, and the walls of the tower are up to 22 feet thick near its base.

7. ITS ARCHITECTURAL STYLE QUICKLY FELL OUT OF FAVOR.

Influenced by Paris’s Tuileries Palace and the New Louvre Palace, McArthur, who trained under U.S. Capitol architect Thomas U. Walter, designed City Hall in a style known as French Second Empire. Developed during the latter part of the 19th century, the style—also known as Napoleon III or Second Empire Baroque style—features a large, freestanding structure, a high mansard roof, and lots of classical detail. But when the building opened in 1901, critics derided its opulent style and chastised its archaic nature for decades.

8. A SCOTTISH IMMIGRANT SCULPTED THE FAMOUS PENN STATUE.

Alexander Milne Calder arrived in America in 1868 and studied at the Pennsylvania Academy of Fine Arts. He spent 20 years working on sculptures for City Hall, but the 37-foot, 27-ton statue of William Penn literally stands above the rest. Details include a copy of the Charter of Pennsylvania, a tree stump, decorative lace cuffs and buttons, and Penn’s hand extended to offer a blessing.

9. CALDER AND HIS SON CREATED THE MOST “ORNAMENTED” BUILDING IN AMERICA.

Along with the Penn statue, more than 250 sculptures were created by Calder and his son, Alexander Stirling Calder, for City Hall. Nine of the statues were cast in bronze, while most were started in clay, cast in plaster, and finished in marble. There are nods to naturalism and animals, Swedish settlers, mythological creatures, Native Americans, a group of cats chasing some mice, and four eagles with 15-foot wingspans near the top of the tower.

10. DETRACTORS WANTED TO DESTROY THE BUILDING IN THE 1950S.

When it was only half finished, a newspaper called City Hall “the biggest and ugliest building in America.” Second Empire architecture was already out-of-date upon the building’s opening, and by the 1950s, whispers had turned to shouts: Plans were drawn up that would have eliminated City Hall (but saved the tower and statue of Penn). But the cost to do so—around $25 million—was too great, as were the logistics of tearing apart such a well-built masonry structure and removing the millions and millions of bricks and tons of stone. The building remained, and opinions began to sway with the restoration of Conversation Hall in 1982.

11. IT'S ONE OF AMERICA'S MOST HONORED ARCHITECTURAL STRUCTURES.

In 2007, the American Institute of Architects conducted a poll [PDF] to determine the 150 favorite pieces of American architecture, and at number 21 was Philadelphia City Hall. The building is a National Historic Landmark and was added to the National Register of Historic Places in 1976; it was also cited as a National Historic Civil Engineering Landmark in 2006.