Hmm, never noticed. Guess it falls under "I don't stop to smell the roses" anymore.
There is a bus loop behind the UK Flood Gate. Buses for events drop off and pick up guests attending some events at the WSP. After getting off the buses and usually going through a special Security station, guests will either walk out through the UK gate and enter the WSP through the WSP gate. Or if there isn't a visual impact needed, there is a side pathway directly into the WSP circumventing the UK gate.
Not that guests are allowed back there, but if you do find your way backstage via the WSP, you come out in backstage Canada.