Blackheath Gate is here: http://goo.gl/maps/rjJ8d It's where the park meets the heath, the tea hut is all of 200 yards up the road so there will be plenty of opportunity to grab a cuppa while waiting.
Dunno bout the security barriers but it's right by the A2 so can't be that far behind enemy lines, just look for a bunch of hipsters with bikes.
Blackheath Gate is here: http://goo.gl/maps/rjJ8d It's where the park meets the heath, the tea hut is all of 200 yards up the road so there will be plenty of opportunity to grab a cuppa while waiting.
Dunno bout the security barriers but it's right by the A2 so can't be that far behind enemy lines, just look for a bunch of hipsters with bikes.