Authentic treehouse experience! PLEASE READ FULL DESCRIPTION. Stay in a beautifully designed tree house that graces the branches of an old beech tree. Wake up with fresh air in your lungs and a sunrise over Lake Hartwell! Breakfast is prepared in the Main House (across the bridge) every morning just for you. The Seneca Treehouse Project is a learning center for sustainable development. We invite you to ask questions and tour the site. Your tree-house adventure awaits!