The purpose of my research is to identify the legal actions and/or administrative mechanisms established by the Colombian regulation that seek the prevention of the so-called orphan environmental damages caused by the exploration and exploitation of minerals by illegal miners within the territory. Moreover, I will determine whether or not landowners should be responsible for the environmental damage caused by illegal miners, in the case where they do not denounce the illegal activities occurring on their property to the government. In other words, the idea is to review the current regulation, and determine whether landowners should be responsible for the activities caused by third parties (illegal miners) on their properties, and if so, which legal actions should be filed by landowners in order to avoid responsibility in those cases. Hence, I will review which special duties landowners may have with respect to illegal mining on their properties, and which legal actions they should file before competent governmental authorities in order to inform them of these illegal activities. This would have the purpose of helping the government to stop the illegal activities by having the information about where these activities are being carried out, and therefore, prevent the appearance of new environmental damages. By this point, it may be clear that denouncing illegal activities is just a small part of the solution. In order to stop illegal mining it would be also necessary to reflect on the current environmental, social, economical, and cultural policies, strategies and programs. However, the law might contribute to find out a plausible solution. Notwithstanding the above, it is important to point out that I will focus my research only on the identification of the different legal actions, and not on their application and enforcement. Hence, the questions that I will try to resolve will be: (i) whether or not landowners have any special duty of denouncing the illegal mining activities that might take place on their properties (based on the ecological function of the property constitutional principle) (ii) which are the available legal actions and administrative mechanisms under Colombian regulation that should be used by a landowner in order to avoid responsibility and prevent orphan environmental damages caused by the performance of illegal mining activities on their property. I will however not analyze the application of these actions on a day-to-day basis; I will address some of the concerns with respect to the current system.