In this excellent museum dating back to 1835, you'll find eclectic collections covering everything from local history and 18th-century costumes to geology, Victorian toys and ancient Egyptian artefacts. The bramble-covered ruins of Walden Castle Keep, built around 1125, lie in the grounds.
There's a sandpit for young archaeologists and a fascinating 'Worlds of Man' collection, ranging from West African carvings and weaponry to Inuit bone harpoons.