Citizens of European Union and Switzerland, Norway, Iceland and Liechtenstein do not require a visa to travel to Spain, all they need to carry is either their IDs or passports. For minors from these regions, they can visit for up to 90 days with a written parental permission. People from the below mentioned countries can travel to Spain with just a valid passport:
Andorra, Argentina, Australia, Bolivia, Brazil, Brunei, Canada, Chile, Costa Rica, Croatia, El Salvador, U.S.A, Guatemala, Honduras, Israel, Japan, Malaysia, Mexico, Monaco, Nicaragua, New Zealand, Panama, Paraguay, The Republic of Korea, Romania, San Marino, The Vatican, Singapore, Uruguay, Venezuela