Has anyone stayed in these? I am looking for a castle or palace (something really old) to stay in in Madrid, Seville, western andulucia area. thanks

We stayed in 4 different Paradores last year. Many, but not all are in historic buildings, at least a portion of the hotel. Some are well located near sites, others are remote. There is an excellent web site with pictures and maps.
If you are over 59, they are an excellent bargain, if booked directly. We paid around $70 per night, including breakfast for 2. There are also packages for booking 5 nights of different Paradores. Book by telephoning (I speak Spanish, so I don't know if they speak English, but it was fast and efficient and confirmed by fax) or faxing direct, as some discounts are not available through the U.S. booking office. http://www.parador.es/ingles/85clicks/buscador.html
I don't believe there is one in Madrid proper. Also, the most popular ones (Alhambra & Leon) are very difficult to reserve, so plan early.

There are is not a parador in Madrid or sevilla "in town" in both places if you want a parador you have to stay outside,
In madrid Chinchon, about 45 Km away and seville Carmona, About 40 Km again.
You need a car to move from these Paradors into town.
In madrid I will suggest the Hotel Victoria in Plaza de Santa Ana,
and in sevilla Hotel Doña Maria near the cathedral. both are good old Looking hotels with modern bahtrooms.

The parador in Nerja is fabulous, right on the cliffs of the M. Sea. It's east of Malaga so you don't have the congestion of Costa del Sol.
In Seville spend the money to stay at the Alfonso XIII. It's well worth every penney.
We are going back for eleven days, and bought a dream week pass to cover six of those days. We are traveling between Hondarriba and Santiago.

The Parador in Arcos de la Frontera (2 hours South of Seville) is wonderful, high on a hill in the old town with wonderful views over the castle. The rooms have balconies with the same views. Seville does not have any Paradores but there is a highly rated one about 30km away in Carmona.

Hi , I agree with former postings, we have stayed extensively in Spanish Paradores, taking advantage of their promotional offers, the one called Años Dorados is the one we used more frequently. We have been always amazed for the great places and the great dollar-value rate.
Breakfast are particularly good. Paradores Restaurants vary in some are very good in others so so.
Near Madrid you have also Avila, and Segovia with paradores and going east one very nice in Cuenca which is a wonderful destinatiion.
Some are right in the center of town like the one in Plascencia ( in Extramadura on the way to Andalucia) it is one of of the newest paradores built inside a former Convent, the one in Caceres is also inside the Historic area of Cuencia, the one in Toledo has great views but is not in the center of town. The one in Salamanca everybody says it is not worth it first because it is far for the center of town secondly because it is a modern building without charm.
Only a little North of Sevilla is Merida a lovely place to visit rich in Roman History . The Parador in Merida is very nice too.
We stayed in the Hotel Doña Maria in Seville and although the location is perfect we didn't care for the hotel. Casa de la Juderia might be a better choice. Good luck.

...sorry I meant the Parador in Caceres is inside the Historic o Mornumental Area of Caceres. In Extramadura, very near there is the Parador of Trujillo in the city Trujillo.