Travel Hammock gives you two pieces of very thin yet strong rope/cord. The idea is to loop it around a tree and attach it to an "S" hook on either side of the hammock. It holds fine, but if you're concerned about the tree, it will dig into it a bit. Some manufacturers offer a fairly easy solution to distribute the weight of the rope/cord against the tree. For example, Hennessey uses a 3" wide piece of nylon strapping with a loop on either end. The nylon strap goes around the tree and the hammock rope/cord slides into the loop. Because the nylon strap is wider then the rope/cord, it disburses the weight better and doesn't damage the tree. You can make something like that yourself and I think Hennessey sells them for something like $15/set.