Error on city, region, country

First of all, excuse my english.
When I search for something in the city of Salamanca (Spain), it appears in the “Search Results” the posible objects with their city, province, region and country, but objects located in Salamanca have a wrong province or region or something, ‘Sierra de Gredos’, and allways appears the post code 37007, that obviously is not the code of the whole city. I don´t know where this information comes from, because all tags are correct for the node of the city and the boundaries of the province.

Example: Search for Calle San Pablo (San Pablo Street): Result: Calle San Pablo, Salamanca, 37007, Sierra de Gredos, Spain.
Why 37007 and Sierra de Gredos? How can I correct it?

Thanks for your help

Where are you getting your maps from?

What do you mean?
I´m talking about the OSM map.

The standard option for the search on is Nominatim. There’s some details about how it works here, and how to fix wrong addresses:
You can also use
Search for a place, then click the link for “Details” to get more info on how that address was calculated.

Thank you very much. The problem was a node (Sierra de Gredos) taged “region”, that wasn´t a region, but it was relatively near. I have corrected it and now I´ll wait till the database is updated to check if the problem is solved.