Zafra
Zafra is one of the prettiest towns in southern Extremadura, as well as being extremely accessible due to its position by the North-South Via de la Plata motorway.
Known as Sevilla la Chica (the Little Seville) thanks to architectural similarities, especially its courtyards, white houses and alleyways overhung with carnations, the town is well worth an overnight stay if you can squeeze in more than a day trip. I say this because its cobbled streets and two main squares (grande and chica) take on extra enchantment after dark, making a evening stroll round Zafra perhaps my most memorable experience in southern Extremadura.
The gorgeous Parador, a converted castle, is another spot that shouldn't be missed during your visit. More info on Paradores can be found in the accommodation section, but suffice to say this is arguably the most impressive one in Extremadura. Non-residents can pop in for a coffee or beer, and I'd recommend doing so even if your wallet can't stretch to a longer stay.

An extra excuse for spending the night in Zafra is its surfeit of excellent eating places for a town of its size. Recommendable restaurants are scattered all over. This guide doesn't normally get involved in promoting establishments, but I have to say that a personal favourite is La Rebotica, just off La Plaza Chica. The food's great, but what makes it special is the English-speaking owners' relaxed yet meticulous attitude and attention to ensuring you enjoy your meal without feeling fussed over. Booking in advance is recommended, as they've only got a very few tables.
One good trip from Zafra is to the nearby village of Feria, to be found just off the Badajoz road. The centre is full of narrow streets and white houses, while the castle offers great views of the surrounding countryside and has a road up to it, thus enabling you to dodge an otherwise strenuous climb.