The Berwick-upon-Tweed entry on the Wikipedia has the following detail - Since Berwick had changed hands several times, it was traditionally regarded as a special, separate entity, and some proclamations referred to "England, Scotland and the town of Berwick-upon-Tweed". One such was the declaration of the Crimean War against Russia in 1853, which Queen Victoria supposedly signed as "Victoria, Queen of Great Britain, Ireland, Berwick-upon-Tweed and all British Dominions"
the Treaty of Everlasting Peace [between Scotland and England in 1502] stated that Berwick was of England but not in England, so Berwick was always mentioned separately in Acts of Parliament. - read more at www.culture24.org.uk
So that's a good enough reason to visit, and then there's Holy Island and the Farne Islands as well!
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