a town of Portugal, in Estremadura, with a castle said to be impregnable. It is fortified both by art and nature, being built on the top of a rock exceedingly steep on all sides. The salt produced here, whence the town takes its name, is of remarkable whiteness. The fields produce large quantities of rushes, of which mats are made, which are transported out of the kingdom. Pop. 4000. Long. 9. 10. W. Lat. 38. 18. N.