Londonthorpe is both a small village and a large parish. The parish is about 110 miles north of London and lies about three miles east of Grantham along the old Ermine Street (now the B6403). The parish itself is bounded on the north by Belton parish, to the east by Welby parish, west by Grantham, and to the south by Somerby parish. The parish covers about 1,710 acres.
The village of Londonthorpe is about three miles northeast of Grantham's center and just east of Belton House. If you are planning a visit:
It is probably easiest to take the A52 east out of Grantham, then north on the B6403 about three miles brings you to Londonthorpe on the west side of the road.
The name derives from the Old Scandinavian lundr+thorp, meaning "outlying farmstead or hamlet by a grove". It appears as Lundertorp in the 1086 Domesday Book. You will find more recent spellings both with and without the final "e", and also split into "London Thorpe," etc. A. D. Mills, "A Dictionary of English Place-Names," Oxford University Press, 1991.