Hill house, Monmouth (General)
I believe Hill House was the name given to the old Monmouth Poor Law Institution when it passed from the control of the Guardians to the Local Authority. As with many such Institutions many of the functions continued after abolishment but under another name.
In this 1920 revision:-
https://maps.nls.uk/view/101453331
In this 1940 revision:-
https://maps.nls.uk/view/101453328
In both cases look just north of Monmouth on the Hereford Road.