Heart of Midlothian

The Heart of Midlothian, also known as the Old Tolbooth, was a prison in Edinburgh, which appeared to be a cross between a town hall and a castle. It was also the office of the Lord Provost. It was a medieval building which blocked off half the High Street and was built sometime prior to 1645.

The Twelfth Doctor pointed out the Heart of Midlothian and nearby St Giles' Cathedral to prove to Bill Potts that they were in Edinburgh. (PROSE: Plague City)