World Heritage Sites are places that the World Heritage Committee of UNESCO has inscribed on a list of international sites because of their outstanding universal value, the importance of which is so great as to transcend national boundaries. Countries with world heritage sites are required to afford the highest level of protection to these places, which means not only looking after the sites themselves but also their setting. This inevitably results in some constraints upon tree planting within world heritage sites. Any woodland creation within these areas has the potential to impact on the heritage site, and so Cadw should be liaised with to discuss any special guidance or general requirements in these areas. For more details, see GN002.