Final answer:
One legal threat to the archaeological heritage is the degradation caused by excessive tourism and unregulated activities, while an illegal threat is the looting and illegal excavation of sites.
Step-by-step explanation:
An archaeological site can be threatened both legally and illegally. One legal threat to the archaeological heritage is the degradation caused by excessive tourism and unregulated activities. For example, tourists touching the walls, digging in the ground for artifacts, or vandalizing carvings can damage the site. This is a legal threat because it is not illegal for tourists to visit the site, but their actions can still cause harm.
On the other hand, an illegal threat to the archaeological heritage is the looting and illegal excavation of sites. Individuals who dig up and remove archaeological materials for private collection or sale are conducting illegal activities. This is a significant threat because it destroys the archaeological context of the site and often involves the removal of cultural artifacts and human remains.