The Black Gate

Built between 1247 and 1250 during the reign of
King Henry III, the Black Gate was the last addition
to the medieval Castle defences.  Consisting of an
arched passage, with what are thought to be guard
chambers on either side, it was the gatehouse of the
barbican, a walled, defensive entrance passage for
the Castle's North Gate.  The gatehouse
could be sealed by a portcullis.

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The Black Gate
Newcastle Castle
Newcastle Castle (Wikipedia)