Here is a map of the Alentejo region showing the location of Estremoz (the red star). The purple stars represent two interesting sites.
Vila de Frades has an interesting wine tradition. Called Vinho de Talha, the wine is produced in 1400 liter vats just as the Romans did. The wine is ready on November 11th, and a celebration of the resulting wine called Vitifrades commences at the start of December (the dates are December 6-9 in 2007).
Monsaraz (see pictures of Mansaraz) is a beautiful whitewashed village on a hill near the man-made Alqueva Lake, which has recently started boat services so that you can see other villages via ferry.
There are many wineries to visit in the area. We highly recommend a visit to nearby Monte Seis Reis.