The aim of the study was to determine the types of changes – depending on season and tourist traffic – occur in the array of fungi in selected adits in Lower Silesia (Ciechanowice, Rozdroże Izerskie or Izera Crossroads, Kletno – Sztolnia Wiejąca or Windy Adit, and Kletno – Sztolnia Turystyczna or Tourist Adit). Air samples were collected by impact method in 2015-16. The dominant fungi in the adit air were the ones of the genus Penicillium and of the species Cladosporium cladosporiodes. The mycobiota of each adit varied to a certain extent; the differences, however, were more pronounced between the adits, which are inaccessible to the public and the Tourist Adit in Kletno. It was demonstrated that the presence of tourists exerts a marked influence on species composition and the number of fungi and spores in caves and underground facilities. This may greatly affect the biological and historical maintenance and stability of these sites.