Sealand, a concrete fortress off the Suffolk coast is up for sale.

Sealand, a Maunsell Sea Fort, was constructed by the UK the during World War II as an anti-aircraft base; then, in 1967, Major Paddy Roy Bates moved in and claimed sovereignty and in doing so created the principality of Sealand which is the smallest independent nation in the world (it has its own flag, passports, currency and stamps).

Since 2000 the data centre HavenCo has operated from Sealand which provides a tax haven, sheltered from UK government regulation and most other legal restrictions.