Found in 2 comments on Hacker News
Hijack for good:

If you guys love this story, read this: https://www.amazon.com/Unruly-Places-Spaces-Inscrutable-Geog...

Its a book about places with odd borders, histories and futures that is tantalizing.

The full Sealand story is told here an its breathtaking.

zukzuk · 2018-12-16 · Original thread
Great book about these and other geographical oddities: https://www.amazon.com/Unruly-Places-Spaces-Inscrutable-Geog...

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