Housed in the unique setting of the former All Saints Church since 1958, the museum focuses on the rich natural history of north-east Essex.
The nave and chancel are the oldest parts of the existing church and their proportions suggest that they are Norman.
The north aisle and tower are more recent additions. The shape of the windows is typical of gothic architecture which dates them to between 1375 and 1550.
In 1648, during the English Civil War, St Botolph's church was badly damaged. The parishioners were welcomed at All Saints where they attended for nearly 200 years until 1837 when the present St Botolph's church was built.
All Saints became redundant in 1956 due to falling numbers of the congregation as the population in the town centre diminished.
The Natural History Museum opened in 1958 with displays on the wildlife and geology of the north east Essex area. The animal specimens on display are made from the skins of real animals. The skin is removed, preserved and arranged around a model of the original body. The majority of the specimens on display have been made from animals found by the roadside.