The Spanish Cadastre website allows the access to the general database for the municipalities covered by the system. As the Basque and Navarre provinces enjoy a different fiscal regime, they have their own, independent cadastres.
You can access the system through the cadastral reference (a single code atributed to each property) or by a graphic map for each municipality.
The system provides information about the buildings in the lot, the internal distribution of uses and areas, and other features. As with any database, there are some flaws, but overall is a pretty good service: for instance, the new Ayuntamiento building was built in the 1910s, but the building date in the database refers to the recent refurbishment.