Trans-frontier areas are 'nerve spots' where for geographical, economic, linguistic or other reasons, the new needs for cooperation are becoming increasingly urgent. They are the terrain for immediate cooperation across frontiers on problems which cannot be dealt with at a national level. Examples of such problems include: communications, water management and purification; frontier traffic; the socio-cultural interests of small municipalities; and recreational facilities. Trans-frontier cooperation is necessary not merely to establish coordination for the area in question, but to facilitate economic and cultural growth for all the countries involved.