Robin exits the Tube at Oxford Circus on the night of her 30th birthday. 

“Robin could feel the new opal resting in the hollow of the base of her throat as she walked toward the Tube station along the road, and having slept properly for once, and having clean hair, and carrying a feeling of lightness with her that had persisted ever since she took the balloon donkey out of his box, she attracted many pairs of male eyes in the street and on the train. But Robin ignored all of them, heading up the stairs at Oxford Circus, and then proceeded down Regent Street and, finally, to the Shakespeare’s Head where she saw Strike standing outside, wearing a suit.” Troubled Blood, Chapter 73

Robin walked down Regent Street on her way to the Shakespeare’s Head. 

Find Oxford Circus Station on the map below: