What is the fine-grained topic of the following text: Although brochures explain that it is the highest cliff in Europe, at least five European cliffs (Hornelen at 860 metres, Cape Enniberg at 750 metres, Vixía Herbeira at 613 metres, Preikestolen at 604 metres and Slieve League at 601 metres) are higher. Only return the topic.
European cliffs