Originally coming into force in 1995, the Schengen Agreement effectively removed internal borders, allowing EU citizens freedom of movement. As of writing, 22 EU countries (out of 28) are Schengen countries and are joined by another 4 non-EU countries. The 6 EU countries currently outside the Schengen Zone are the United Kingdom, Ireland, Croatia, Bulgaria, Cyprus and Romania. Andorra and San Marino are neither in the Schengen Zone or the EU but they have removed border controls for Schengen citizens. As a Spanish city, Barcelona is in the European Union and being in Spain, it is also subject to the Schengen Agreement.
European Visitors: The Schengen Agreement does not mean you can travel without a form of identification. All Schengen and other European visitors still require either a Passport or a National Identity Card in order to travel through the Schengen zone without being subject to border checks (except when border controls are temporarily reinstated under Schengen Rules – usually for threats to security).
Non- European Visitors: Valid passports and visas are required by citizens of Non-EU countries to enter Barcelona. Visas are discretionary and can be applied for via your home country procedures. It is also important to understand the rules regarding visitors for your home country with regard to airport transfers because in some cases, a transfer visa is required. The full (current) list of countries that require Schengen Visas and Schengen Transfer Visas is available here. A short term Schengen visa is currently €60, but under a special visa facilitation agreement only €35 for citizens of some countries (like Russia and Ukraine).
Vaccinations and Medical Info
No vaccinations are required to enter Barcelona or Spain but if during your stay you intend to venture into rural areas, it is advised that your anti-tetanus is up to date. Some government health sites (such as the one for USA) suggest a Hepatitis A vaccination is advisable if you’re venturing into rural areas where food hygiene might be questionable, but this entirely by choice and not a specific recommendation.
Comprehensive travel insurance will cover most medical emergencies because all nationalities will receive free or reduced-cost necessary treatment should they become suddenly ill or be involved in an accident while visiting Spain. Despite this, Europeans are advised to travel with a valid European Health Insurance Card which is obtained in your home country. Application through official government channels is free.