Every year, foreign buyers lose money on Spanish land that they cannot legally build on. The listing said "buildable" but the catastro disagrees, or the land is classified as rústico with no construction rights, or there is a protected watercourse cutting through the middle of the plot. Here is how to avoid this.
Check 1: The catastro
The Catastro is Spain's official land registry for tax purposes. It shows: the plot boundaries and area, the land classification (urban, rustic, or special), any existing structures on the plot, and the catastral reference number. You can check basic catastro data for free on the Sede Electrónica del Catastro website. However, the catastro is not always accurate — boundaries can be outdated and classifications may not reflect recent zoning changes. Always cross-reference with the Registro de la Propiedad and the municipal plan.