This contribution will examine intentional acts of terrorist groups and organised networks directed against cultural heritage as a challenge for international law, e.g., by creating grey zones. In particular, it will be asked to what extent criminal law enforcement can be identified as a missing link in the system of the legal protection of cultural property, including World Heritage. It is seen as necessary to strengthen criminal sanctions for possession and sale of illegally trafficked cultural objects. In that respect, it will be argued, the Nicosia Convention on Offences Relating to Cultural Property, adopted by the Council of Europe in 2017, may give new impetus to criminal law as a tool in the fight against offences against cultural property, helping to reduce lawless areas. Cultural heritage protection, it is emphasised, requires a robust, legally integrated approach, including criminal prosecution for plundering, smuggling, and destruction.