trol of the air space, air traffic and transport; meteorological services and aircraft registration.
21. Railways and land transport crossing through the territory of more than one Self-governing Community; general system of communications; motor vehicle traffic; Post Office services and telecommunications; air and underwater cables and radio communications.
22. Legislation, regulation and concession of hydraulic resources and development where the water-streams flow through more than one Self-governing Community, and authorization for hydro-electrical power plants whenever their operation affects other Communities or the lines of energy transportation are extended over other Communities.
23. Basic legislation on environmental protection, without prejudice to powers of the Self-governing Communities to take additional protective measures; basic legislation on woodlands, forestry and cattle trails.
24. Public works of general benefit or whose execution affects more than one Selfgoverning Community.
25. Basic regulation of mining and energy.
26. Manufacturing, sale, possession and use of arms and explosives.
27. Basic rules relating to organization of the press, radio and television and, in general, all mass-communications media without prejudice to powers vested in the Self-governing Communities for their development and implementation.
28. Protection of Spain's cultural and artistic heritage and national monuments against exportation and spoliation; museums, libraries, and archives belonging to the State, without prejudice to their management by the Self-governing Communities.
29. Public safety, without prejudice to the70
