This study defines and discusses the natural patrimony represented by monumental trees, i.e. large old trees of native tree species from Chile. These trees should be preserved because they: 1) foster natural fascination, 2) are rarities of nature, 3) provide ecosystem services, 4) allow the study of individual adaptations, 5) represent a biocultural patrimony and 6) have been strongly exploited. It is proposed to conduct a national survey of monumental trees and develop policy instruments to protect these trees.