For book lovers, architecture enthusiasts, and travellers who read a place through its past, some libraries offer more than quiet rooms lined with manuscripts. A rare few are set within UNESCO World Heritage Sites—meaning that whether they are perched on hillsides, embedded in historic city centres, or surrounded by forested mountains, they show how knowledge has been shaped, stored, and protected across centuries. From monastic scriptoria and Renaissance design experiments to purpose-built repositories for sacred texts, each space reflects the intellectual and cultural priorities of its time. Below are seven stunning libraries housed within UNESCO World Heritage Sites, from Portugal to South Korea and beyond.