Walmgate -The English city of York has, since Roman times, been defended by walls of one form or another. To this day, substantial portions of the walls remain, and York has more miles of intact wall than any other city in England. They are known variously as York City Walls, the Bar walls and the Roman walls (though this last is a misnomer as very little of the extant stonework is of Roman origin, and the course of the wall has been substantially altered since Roman times).
Most of Walmgate Bar was built during the 14th century, although the inner gateway dates from the 12th century. The Bar's most notable feature is its barbican, which is the only one surviving on a town gate in England. It also retains its portcullis and 15th century oak doors. On the inner side, an Elizabethan house, supported by stone pillars, extends out over the gateway.
The Bar has been repaired and restored many times over the years, most notably in 1648, following the 1644 Siege of York in the English Civil War when it was bombarded by cannon fire, and in 1840 after it had suffered years of neglect. It was also damaged in 1489 when, along with Fishergate Bar, it was burnt by rebels who were rioting over tax raises.
Source & More Information: Wikipedia, York city walls, http://en.wikipedia.org/wiki/York_city_walls