Blue Flag

The Blue Flag is a voluntary eco-label awarded to over 3200 beaches and marinas in 37 countries across Europe, South Africa, Morocco, Tunisia, New Zealand, Canada and the Caribbean. The Blue Flag Programme is owned and run by the independent non-profit organisation Foundation for Environmental Education (FEE). The Blue Flag works towards sustainable development at beaches/marinas through strict criteria dealing with water quality, environmental education and information, environmental management, and safety and other services. The Blue Flag Programme includes environmental education and information for the public, decision makers and tourism operators.
The Campaign gives an award - the Blue Flag - on the basis of criteria on:
Environmental education and information (e.g. information on bathing water quality and the local environment, tours and activities that raise awareness)
Environmental management (e.g. waste, nature protection, sewage treatment)
Water quality (for beaches clean bathing water of a specified quality)
Safety and services (e.g. lifesaving equipment, toilet facilities, first aid)

Because of its amount of sunny beaches the blue flag award is very important for spain.
In total 442 spanish beaches and 72 marinas have received the blue flag as of today.
The full list can be seen here