Alleys are one of the classical elements of open space topography as well as in cultural landscape and city space. These historical plant forms which have survived to our times require special conservatory attention – protective and maintenance works. In this study, one method of evaluating the condition of old trees is presented. The trees are the remains of the alley layout at the former manor house in Zemborzyce. In 2015, an inventory of alley trees was carried out and the internal structures of the examined trees were evaluated using sound tomograph PICUS . The non-invasive method used is especially recommended to evaluate the health condition of valuable, old trees. It allows us to examine each tree extensively and carry out individual procedures according to conservatory rules.