Hi haleyc,
There is a couple of pictures and information about Grantham workhouse in "Bygone Grantham"Volume 2.by Michael Pointer and Malcolm Knapp 1977.pages 32/33.
In 1966 my son was born in Hillview Hospital (a maternity unit)which was built at the back of the old workhouse and you had to go through the original arched entrance to reach it.All the buildings have now been pulled down and a Residential home called Harrison House is now on the site.
Kathy