Friction between grains of sand cause a curious "singing" sound.

An eccentric inventor's castle home with its own indoor weather system.

A dedication plaque on this Boston tunnel is a microcosm of a massive, controversy-laden construction project.

A gift to the children of Boston, this bronze bear represents playfulness, a spirit of love, and the warmth of big hugs.

A beacon atop a downtown building provides Bostonians with weather forecasts and baseball news.

This hotel was the site of major events in sports and radio history. It was also used as a detention center during World War II.

A luxury hotel constructed out of a former jail.

The world's largest piece of copyrighted artwork.

In 1958, an MIT fraternity pledge laid down on this bridge and instituted a new, unique unit of measurement.

An interesting decoration on this historic site, this weathervane comes with as many legends as it does questions.

This impressive Boston holy house is the American mecca for Christian scientists.

Dedicated to one of the darkest moments in Irish history.

The site where Charles Dickens gave his first public reading of "A Christmas Carol" in the US.

This massive tea kettle was once a promotional stunt for the Oriental Teashop.

First planned industrial community in the United States.

These stained-glass windows are all that remains of a building that was the target of one of the biggest explosions in London after World War II.

Once designed as the entrance to Buckingham Palace, this structure was later relocated and stands as a victory arch.

At the top of the hour, figures of the London department store's two co-founders emerge and bow to each other.

The handiwork of a underdog clockmaker who solved an impossible problem for an Empire, and forever revolutionized seafaring.

The bronze uniforms commemorate the vital role of women during World War II.

The first geometric self-supporting spiral stairs in Britain are a truly beautiful sight.

Thanks to modern navigational tools we now know that the true prime meridian runs through a park next door.

A much-loved local landmark pays tribute to the shipbuilding past of this area.

A 1,215-foot tunnel transports pedestrians beneath the River Thames.