Of the walls built by Rama III at Khai Noen Wong to protect the town from Vietnamese invasions in the mid 19C, only a small 50m-long section remains, with a few canons shaded by flamboyant trees. The Underwater Archaeological Museum here is well worth a visit, both for its excellent explanations and for the interesting life-size reconstruction of a junk. Through this model, visitors can learn all about shipping over the centuries, including how goods and merchandise were stored in the ships.