New Palace Yard, the secluded, tree-shaded courtyard where the knifeman was shot, is no stranger to terrorism.
He was brought down yards from the spot where Tory MP Airey Neave was assassinated by the Irish Liberation Army almost to the day in 1979.
I’ve used this entrance thousands of times in two decades of working at Westminster.
In days gone by security at the Houses of Parliament was lax. You could just walk through St Stephen’s Entrance to drink with MPs in the Strangers’ Bar. Not any more.
After Neave was killed by a mercury-tilt car bomb, protection was stepped up.
And after 9/11, stringent checks on visitors were brought in, large concrete blocks were put round the building and bus stops outside the railings were shut down.
But like the bomber, the knifeman can get through if he cares nothing for his life.
The shady courtyard where David Blunkett exercised his guide dog became a scene of terror once again.