Estremoz is one of the Alentejo's three marble towns, and the stone is not just a trade here: it is under your feet, in doorsteps, in stairways, and in the pale houses that climb toward the castle. The local quarries have supplied Portuguese monuments for centuries, but the town itself is the best small lesson in how that marble changes everyday architecture.
The top of town is the place to start. The Castle of Estremoz and its former royal palace stand above a compact old quarter of steep lanes and white walls. Down on the Rossio, the Cloister of the Igreja da Misericordia gives the lower town a quieter historic anchor.
If you can time the visit, come on Saturday morning for the Rossio Saturday Market. It is part flea market, part farmers' market, and part Alentejo food lesson, with cheeses, pottery, tools, and household odds and ends spread across the big square. Estremoz works well as a day trip from Evora, Elvas, or Badajoz, but it rewards a slow morning more than a quick photo stop.