Trusts have always seemed to me to be pretty vulnerable. You have to trust the entire line of future trustees to actually implement what's written down in the agreement. Say I donate my property to a trust set up to keep that property a public park for 1000 years. I choose someone I trust to implement it when I'm dead. But, then that person has to choose someone they trust, and so on, and at some point in the future, inevitably it's going to fall into the hands of someone who would rather sell the land and spend the proceeds on hookers and blow.