The Ipswich Museum covers natural history, geology, and archaeology, with a notable collection of Roman and Anglo-Saxon material from the region. The natural history galleries have that loveable Victorian museum quality — taxidermy, geology cases, a walrus — while the archaeology section is genuinely informative about Suffolk's long history.
The museum is housed in a fine Victorian building on the High Street and admission is free. Worth an hour, especially if you are also planning to visit Sutton Hoo. Opens Tuesday to Saturday.