A visa is not necessary for International Summer School students.
A) European Union citizens:
European Union citizens need to be in possession of a valid European Union identification card or passport; there is no additional visa requirement.
B) Non-European Union citizens:
A student visa is mandatory for non-European Union citizens wishing to study in Spain for three months or longer only. A student visa must be processed in your country of residence prior to your departure. You cannot get the visa in Spain and you cannot have it sent to you. The visa is affixed in your passport before you depart from your country and must be presented to immigration officials upon your entry into Spain.