Visitors to the Museum can see the free exhibition which tells the full story of Sleaford Castle and also shows details of the latest research available.
Civic Trust members will be on hand to explain the findings from the most recent archaeological investigations, which took place earlier this year.
A leaflet will be available to guide visitors from the museum to the castle site and will also explain some of its features.
Visitors will also be able to enjoy the latest presentations and exhibits in the museum, including its celebration of five years in operation.
The museum will be open on both Saturdays (September 12 and 19) from 10am until 3pm, and both Sundays (September 13 and 20) from 11am until 3pm.
Admission is free, but donations are welcome in support of the work of both the Civic Trust and Sleaford Museum.