Built in the XIII century, this 'Palacio' is belonging since then to Duques de Medina Sidonia family. Guided visits are organized normally on sunday (need to reserve), but one charming side of the building and the garden serves as 'cafè' and open every day from 8.30 to 21.00 (02.00 in summer). Another side of the building serves as 'hospederia' (hostel), so at reasonable prices it's possible to sleep in a piece of history!
The Palacio is well known for its archives (unfortunately opened only to academics or accreditated people), that preserve some of most important medieval and political documents and maps.
If you decide to visit the Salinas and Bonanza in Sanlucar, please consider that is not so easy! You could reserve your visit by touristic train calling the provided number (cost:12 euros), but it's normally necessary to reach a sufficient number of people (they didn't say how many). So if you are 2 or 3 persons it's better to organize a visit on your own. We found there is the direct bus number 1 (direction Algaida) wich can take you there every 20 minutes (cost: 1 euro), but you can only see the mountains of salt from the street and the factory exterior. Anyway, is a very beautiful (and blinding :-) view!
Surrounded by buildings that make up the extensive Barbadillo sherry bodega, the remains of the 15th century castle can be viewed but not entered as it is currently closed until funding can be secured to complete renovations. It's a short walk east of the Iglesia de Nuestra Senora de la 0.
Built in the 15th century, the church has an interesting neo-Muslim doorway and according to guidebooks has a beautiful Mujedar ceiling which we were not able to view because it was late on a Sunday evening when we visited.
This building with neo-Muslim and Baroque architectural elements on its exterior was once used as a summer home for a powerful Sanlucar family in the 19th century. It's now used as the town hall (ayuntamiento) but is open to the public for viewing. Check to join the free guided tours. Admission is free.
Not entirely sure what this area was used for according to the historical text marker on site, Las Covachas is a lovely Gothic facade in what is the basement level of the Palacio de los Duques. The facade, built in the 15-th century, includes nice arches and motifs of sea monsters. It's also located on the pretty hill street of Calle Bretones/Calle Cuesta de Belen.
Difficult to find, just at the end of the Guadalquivir, a nice town, in front of the Donana park-there is a ferry crossing the river- and some km north, the fishermen harbour...I love harbours,so....