Walmgate Bar is architecturally the most complete of York's four medieval gateways. It is the only city gate in England still possessing its original barbican — the projecting defensive structure beyond the main arch that forced attackers into a confined killing ground. The original iron portcullis and oak doors remain in place. The barbican dates from the 14th century; the main gatehouse structure is earlier. The combination makes Walmgate Bar a remarkably intact piece of medieval military architecture.
The bar stands on the eastern approach into the city, which was historically the less fashionable end of York; the area beyond the walls here was long associated with industry and poorer housing. This probably accounts for its survival in better condition than the more prestigious western and northern gates — there was less pressure to alter or demolish it. Medieval graffiti on the stone includes the scratched inscription "Wm Stork 1486". The interior chamber is occasionally open to the public.