Theatre Royal. This wall is most of what remains of the 320-seat Theatre Royal, opened on 20th August 1792 by Samuel Butler's touring company, which included Edmund Kean among its actors. Another famous actor, George Bennett, was born nearby in 1800. The building, later a military riding school and a drill hall, was mostly destroyed by fire in 1918.

Mike Kirby on Geograph
Richard Collier on Wikimedia Commons
See also...
Simon Harriyott on Flickr
Simon Harriyott on Flickr
bardwellpeter on Flickr CC0
Simon Harriyott on Flickr
flipflopnick on Flickr