Akademik

Play House Yard
   East out of Water Lane, Blackfriars, to Church Entry. In Farringdon Ward Within (P.O. Directory).
   First mention: 1637 (L. and P. Chas. I. IX. 180).
   In Horwood, 1799, the eastern end is called " Glass House Yard" (q.v.).
   Called" Glass House Yard" (Rocque, 1746).
   Named after the Blackfriars Theatre, which stood here 1596-7 to 1665.
   A portion of the old wall was found here and a monument erected to a" speculator" of the second legion, apparently work of the first century, also a coin of Trajan and of Constantine.

A Dictionary of London. . 1918.