It's about 100 times as heavy as The Great Pyramid of Giza.
In other words, 660 megatonnes is 110 times the weight of The Great Pyramid of Giza, and the weight of The Great Pyramid of Giza is 0.0091 times that amount.(a.k.a. Pyramid of Khufu, a.k.a. Pyramid of Cheops) (Cairo, Egypt)
The Great Pyramid of Giza has an estimated mass of 5.90 megatonnes. The 2,300,000 stones used in the construction of the pyramid weighed an average 0.00000230 megatonnes and were quarried from distances of up to 805 km (500 mi) away.
It's about 800 times as heavy as The Golden Gate Bridge.
In other words, 660 megatonnes is 820 times the weight of The Golden Gate Bridge, and the weight of The Golden Gate Bridge is 0.00122 times that amount.(San Francisco, California and Marin County, California) (Post 1986 weight reduction; total weight of bridge, anchorage, and approaches)
Following the completion of the 1986 project to eliminate excess material, the total weight of the Golden Gate Bridge — including its anchorages and approaches — is 0.8050 megatonnes. The two main cables in the spanning the bridge are spun out of a total of 129,000 km (80,200 mi) of wire.
It's about 2,000 times as heavy as The Empire State Building.
In other words, 660 megatonnes is 1,990 times the weight of The Empire State Building, and the weight of The Empire State Building is 0.000503 times that amount.(New York City, New York)
The Empire State Building weighs approximately 0.3310 megatonnes. About 4% of the building's weight is its 6,000 cu. m (200,000 cu. ft) of limestone façade.
It's about 3,500 times as heavy as The Sears Tower.
In other words, 660 megatonnes is 3,271 times the weight of The Sears Tower, and the weight of The Sears Tower is 0.0003057 times that amount.(officially "Willis Tower" as of 2009) (Chicago, Illinois)
The Willis Tower weighs approximately 0.20180 megatonnes. The outer wall surface of the Tower is covered with black anodized aluminum panels which would total 110,000 sq. m (28 acres) if laid out together.
It's about 5,500 times as heavy as The CN Tower.
In other words, 660 megatonnes is 5,597.50 times the weight of The CN Tower, and the weight of The CN Tower is 0.00017865 times that amount.(a.k.a. La Tour CN, a.k.a. Canadian National Tower, a.k.a. Canada's National Tower) (Toronto, Canada)
The CN Tower weighs approximately 0.117910 megatonnes. The Tower is home to the world's highest glass floor — a viewing area that allows visitors to look straight down 342 m (1,120 ft) to the ground below.
It's about 25,000 times as heavy as The Statue of Liberty.
In other words, 660 megatonnes is 26,800 times the weight of The Statue of Liberty, and the weight of The Statue of Liberty is 0.00003730 times that amount.(a.k.a. Liberty Enlightening the World, a.k.a. La Liberté éclairant le monde) (total weight, including foundation)
The total weight of the Statue of Liberty, including her base is roughly 0.0246 megatonnes. 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 50,000 times as heavy as The Brooklyn Bridge.
In other words, 660 megatonnes is 49,550 times the weight of The Brooklyn Bridge, and the weight of The Brooklyn Bridge is 0.000020180 times that amount.(a.k.a. New York and Brooklyn Bridge) (Manhattan and Brooklyn, New York City, New York) (total weight)
The total weight of the Brooklyn Bridge is approximately 0.01332 megatonnes. In a promotional event to prove the bridge's stability shortly after it opened, entertainer P. T. Barnum led a parade of 21 elephants across it in May of 1884.