Everingham is a fictional estate in Norfolk, England. Everingham is where Mansfield Park's Henry Crawford was born, and he is also the heir to receive Everingham. This is a setting for several scenes in Mansfield Park. 

Austen, Jane. Mansfield Park, edited by June Sturrock, Broadview Press, 2003.

The image attached is a map of England. Norfolk is represented by the highlighted red region. Everingham would be located here.