This observation tower is a longstanding, 1960s landmark in the Thousand Islands region of Canada.

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

Liechtenstein's royal family calls this medieval alpine castle home.

If you fly into Edinburgh Airport, it's possible to spot this prehistoric site without even getting off the plane.

Edinburgh's oldest statue hides within a parking lot behind the city's iconic cathedral.

The dance of this huge clock is a magnificent and eerie commentary on good and evil in the history of humankind.

A six-ton wedding present for the King of the Scots.

Overlooked by many, the two famous Scottish warriors guard the main gate of Edinburgh Castle.

The taxidermy remains of the first mammal ever cloned from an adult cell are on display in Edinburgh.

There are plenty of wonderful panoramic vistas in Edinburgh, but not many are hidden smack in the middle of the Old Town.

The ruins of this gorgeous clifftop castle look like something from a fantasy novel.

After the comedian dissed a Connecticut town on his show, they named a sewage treatment plant after him.

This sound-art installation features songs composed using only the Mid-Hudson Bridge as an instrument.

A sweet symbol marks the place where torturous executions were once carried out.

This 17th-century street hidden beneath Edinburgh was once a breeding ground for the black death.

These wooden pipes were crucial to providing water to Medieval Edinburgh.

A remarkable feat of Victorian engineering across the Firth of Forth.

A red sandstone freestanding monolith rises out of the sea in northern Scotland.

Enter the world under the hill at this ancient UK burial chamber.

This tin chapel was built by POW's during World War II and is painted to look like something much more grand.

Possibly the oldest of Britain's ancient henges is also one of its most stark.

The discovery of this Neolithic settlement, which contained a Stone Age "cathedral," threw archaeologists for a loop.

The true age of this ancient stone circle is unknown, but its stunning vista isn't in question.

Amazing and mysterious Neolithic settlement on Scotland's Orkney Islands.