Overview:Founded in 1931, the Holden Arboretum is an outdoor living museum that promotes the importance of trees and gardens. One of the largest in the country, the arboretum offers visitors a unique outdoor experience combining over 20 miles of hiking trails with themed tree and plant collections. In September 2014, the Holden Arboretum officially began integration with the Cleveland Botanical Garden. The Arboretum and Botanical Garden are committed to creating a more sustainable planet by building greener, healthier communities and engaging children with plants. The integration of these two organizations will better serve the community through education and outreach programming and an enhanced visitor experience.Ohio, Holden is an outdoor living museum that promotes the beauty and importance of trees and other woody plants to create sustainable and healthy communities in the Great Lakes region and beyond. .