Puzzle 26

John Baez

Which region containing about 40 houses belongs to one country but is entirely surrounded by a ring-shaped portion of a second country, which in turn is surrounded by the first?

A: Nahwa, also known as Nahwá or Nahawa. This is a small enclave belonging to the Emirate of Sharjah, entirely surrounded by a ring-shaped patch of the Sultanate of Oman. This ring-shaped territory is called Madha. Madha, in turn, is surrounded by the Emirate of Sharjah, which is part of the United Arab Emirates. You can see a map of the situation here:

The orange territory is the United Arab Emirates, while the green is Oman. All this is on the south side of the Straits of Hormuz, south of Iran. Here the United Arab Emirates are shown on a much larger scale:

Nahwa consists of about 40 houses lying 8 kilometers on a dirt road west of the town of New Madha. Madha is 75 square kilometers of desert which is mostly empty except for New Madha, which has excellent roads, a good school, police station, a bank and airstrip.

An enclave is a piece of land that is totally surrounded by a foreign country, while an exclave is one that is politically attached to a larger piece but not geographically connected to it. Both Nahwa and Madha are both enclaves and exclaves. Lesotho, completely surrounded by South Africa, is an enclave but not an exclave. San Marino and Vatican City are the only other present-day sovereign nations that are enclaves but not exclaves.

The Wikipedia has a nice list of enclaves and exclaves, which makes pleasant reading for those who, like me, enjoy the romance of obscure geography. According to this article, there are other exclaves within exclaves in the world... and even an exclave within an exclave within another exclave! They're all on the border of India and Bangladesh:

On the India-Bangladesh border in the Indian district of Cooch-Behar, there are 92 exclaves of Bangladesh, with a total area of 47.7 square kilometers. Similarly, there are 106 exclaves of India inside Bangladesh, with a total area of 69.5 square kilometers. 21 of the Bangladeshi exclaves are within Indian exclaves. 3 of the Indian exclaves are within Bangladeshi exclaves. The largest Indian exclave, Balapara Khagrabari, surrounds a Bangladeshi exclave, Upanchowki Bhajni, which itself surrounds an Indian exclave called Dahala Khagrabari, of less than one hectare.

Sources:

The Global Gazetteer lists a population of about 17,090 within 7 kilometers of Nahwa, which sounds like a lot more than 40 houses. Does this include Madha? Inquiring minds want to know.

The mathematician Kevin Bryan saw this page after visiting Nahwa, and sent me a report on what it's like:

I walked from Khor Fakkan up to Nahwa; it's maybe 10-12 kilos from the UAE/Madha border. A restaurant just past the border called the Hilltop is actually owned by a Palestianian-born American and is quite good. In Madha, it's generally just scree-covered mountains and a few date plantations, with small villages every km or two and one larger town (New Madha, perhaps 3000 people?). Nahwa has fewer than 100 houses, including a police station, a shop and an electricity generation station. I didn't meet any Emiratis there; nearly all expats from places like Sudan, Phillipines, Egypt, Bangladesh, etc. Everyone was quite friendly, and perhaps every third or fourth car stopped and asked if I wanted a lift. There is no lodging in Madha or Nahwa that I know of.

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