There's so much concrete in the Hoover Dam that if it had been poured all at once, it would have taken over a century to cool. True or false? The dam contains enough concrete to pave a highway from San Francisco to New York.

How long is the Seven Mile bridge in the Florida Keys?

This is the Cape Hatteras light, the tallest lighthouse in the US. Where is it located? Hint: It's on the Atlantic Coast.

There's a clock carved high up on a wall in New York's famous Grand Central Station (which is actually called Grand Central Terminal--the real Grand Central Station is a post office). As you can see, an engraving just beneath the clock face reads 'Eastern Standard Time'.  True or false? Railroads adopted time zones before Congress did.

What is carved into the pedestal at the Statue of Liberty's feet?

True or false? There is a typo in one of the inscriptions on the Lincoln Memorial--'euture' instead of 'future'.

The widest highway in the world is a section of Interstate 10 in Texas. How many lanes does it have? (And no, that's not it pictured above.)

The first Transcontinental Railroad bridged the gap between the east and west back in 1869. Central Pacific laid tracks heading east from California, Union Pacific worked west from Iowa, and the two parts of the railroad were joined by a commemorative golden spike. Where was this final spike driven?

The famous Gateway Arch of St. Louis has long been a popular target for parachutists to land on and daredevils to jump from, even though it's not entirely legal. True or false? At 630 feet tall, the Gateway Arch is the largest manmade monument in the United States.

The Golden Gate bridge opened to the public in 1937, and by 1985, one billion cars had made their way across--but that's just the human traffic. Which of the following creatures has crossed (or attempted to cross) the Golden Gate Bridge?

The unfinished Crazy Horse Memorial (a model pictured above) has been under construction since 1935. The plan is to depict Crazy Horse pointing towards his ancestral homelands--but maybe that's not such a good idea. True or false? Is pointing considered a taboo gesture in Native American culture?

At 135,000 square feet, the Biltmore Estate is the largest privately-owned home in America. How many rooms does it have?

You might know that the Hollywood sign was originally just a temporary advertisement, but do you know where it's really located? What is the name of the mountain the sign is built upon?

True or false? The spire at the top of the Empire State building was designed to anchor airships like the Hindenburg.

There's a lot of interesting trivia surrounding Mount Rushmore, not to mention some misconceptions. Which of the following claims is completely false?