I stumbled upom a nice new website this evening 'Lost Teesside' . It is part of the FMTTM website and chronicals the lost landmarks of Teesside.
The first entry featured 'North Riding Infirmary' , the ENT Hospital on the corner of Newport Road, which I must have passed many a time on the 266 back to Nunthorpe. Some of the text could be better written but this is Teesside remember.
The second entry is the The Royal Exchange which I seem to vaguely remember. Apparently in it's hayday the Exchange set the world price for Iron and Steel.

The Royal Exchange in Middlesbrough, part of 'Lost Teesside'