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No. 2993:
Enclaves and Exclaves

Today, enclaves and exclaves. The University of Houston's College of Engineering presents this series about the machines that make our civilization run and the people whose ingenuity created them. 

Andy Boyd recently told us about that piece of Minnesota that sticks 25 miles up into Canada. It's mostly Lake of the Woods. But it also includes three bits of land that can be reached only by going through Canada. One of them is only 200 yards wide.

We call those bits, exclaves. That means they can't be reached by land without going outside the US. An enclave, on the other hand, is a portion of a country (or city or state) that's entirely surrounded by a different country. West Berlin was an enclave of West Germany in East Germany, before Germany reunified. 

Vatican City, on the other hand, is not a true enclave, since it's not separated from a mother nation. Rather it might be called an enclaved sovereign nation within the nation of Italy.

Vatican City
Vatican City (Image courtesy of Google Earth)

You can see the complications rising here. Since those bits of American land in northern Minnesota can be reached by boat, they're a special kind of exclave - called pene-exclaves. Alaska is a pene-exclave of the United States attached to Canada, while Hawaii is Federal enclave. We begin to swim in nomenclature.

Of course these separations from the mainland create strange situations. Take Point Roberts, Washington. It's another pene-exclave - a 3 mile by 2 mile rectangle of land dangling from the 49th parallel above the San Juan Islands. The 1300 Americans who live there sell goods and provide vacation facilities to Canadians. 

Point Roberts
Point Roberts, bounded by the 49th Parallel and Canada on the North. (Image courtesy of Google Earth)

Gasoline, food, and liquor cost a lot more in Canada than they do in the US. So Point Roberts is popular with Canadians - for shopping, and for vacationing with its splendid view of Mt. Baker. Those isolated Americans also live in a kind of gated community since border guards keep track of who enters and who leaves. 

I finally went to Engines contributor Krešo Josic as the topology of enclaves grew more and more convoluted. He said he was reminded of the island within a lake on an island within a lake on an island. I thought he was joking until I looked it up.

Sure enough, the island of Vulcan Point sits in a lake in the crater of Taal Volcano in the Philippines. But Taal Volcano is, itself surrounded by Taal Lake. And Taal Lake is in the southern end of Luzon Island. It's like nested Russian dolls. Technically, Vulcan Point is a third-order exclave of the Philippines. 

Vulcan Point and Lake Taal
Vulcan Point, an island within a lake on an island within a lake on an island. (Image courtesy of Google Earth)

And I realized that Krešo had gone to the heart of my problem. We're conditioned to seeing countries as blocks of land next to other blocks of land. Once something slips inside something else, complications arise. As I write, Russia has claimed the Crimea as its exclave, with the Ukraine lying between. I hope, by the time this episode is rerun, that situation will've been resolved.

Meanwhile, thanks to prodding by Andy and Krešo, I have a whole new set of words - words to help me sift the rich complexity of a world that is not at all laid out in neat square blocks. 

I'm John Lienhard at the University of Houston, where we're interested in the way inventive minds work.

(Theme music)

See the very complete Wikipedia article on Enclaves and Exclaves. See also the Wikipedia articles on Northwest Angle (the largest body on land in the "Minnesota Bump," Point Roberts, and Taal Lake.

As soon as this program aired, I received a note from Peter Copeland. He pointed out that someone had only recently discovered an island-in-a-lake-on-an-island-in-a-lake-on-an-island that was larger than Vulcan point. It is presently unnamed and it's on Victoria Island - in the arctic regions of Canada. One can best view it by going to Google Earth and searching on the coordinates: 69.793' N, 108.241" W. It's about a quarter of a mile wide.

Liberty on Bedloe's Island
The Statue of Liberty stands on Bedloe's Island which is an exclave of New York in New Jersey Waters. Click on the image for large view. (Photo by John Lienhard)

This episode was first aired on February 23, 2015