While it might be argued that all trees are "special" (they are!), the University of Arizona Campus Arboretum has placed many trees into Special Collections. These trees, or groups of trees, mark especially monumental development efforts throughout the campus history that resulted in accelerated progress toward the creation of a culturally, educationally and historically useful, sustainable and inspiring campus landscape. These collections house the oldest and largest trees on campus, they confer particular value to the campus landscape and require a high level of horticultural care that merits special attention. These are the trees you will notice first when you visit campus and these are the trees with greatest contributions to the biodiversity and cultural significance of the landscape. You're invited to learn more here through the pages we've provided.