The invention aims to provide a system for detecting attempt to intruding inside the boundary delimited by a fence. The fence includes fence boards fixed onto piles. The system is provided with a detection device for detecting impact and/or vibration which may occur on the fence, and a transferring device for transferring data from the detection device to remote post, which is characterized in that the impact and/or vibration detection device is born by at least one pile. An intrusion attempt detection device including an impact and/or vibration detection device is further provided.