Well, yes, of course. But how can you possibly imply that UNESCO 'controls' a World Heritage Site?
I have rather more than an academic interest in this, since I have the good fortune to live quite close to Stonehenge and even closer to a newly-designated World Heritage Site, the Jurassic Coast of East Devon and Dorset. I've followed closely the determined campaign by the local authorities and other interests over several years to secure this recognition, which is seen by everyone in the area as a great honour. UNESCO has absolutely no 'control' over the Jurassic Coast, which remains entirely in the control of the existing private landowners, local authorities and, in the case of some stretches, the National Trust. The only obligation to UNESCO is to permit monitoring of the Site's conservation and preservation, which can scarcely be described as 'control', since there is absolutely no power to enforce it in the highly unlikely contingency that it would no longer be welcome.