They cover a vast range of subjects from religious studies to mathematics, medicine and astronomy, music, literature, poetry, architecture and esoteric practices, and bear witness to the rich history of the city as a cultural crossroads and centre of learning.

UNESCO: MEDIA SERVICES

In education, the evidence is less clear: international studies of teenagers' prowess in mathematics and science show no clear link to spending levels.

ECONOMIST: Health and education

The global rankings are the result of two studies - the Trends in International Mathematics and Science Study (TIMSS) and the Progress in International Reading Literacy Study (PIRLS).

BBC: Northern Ireland is 'best in Europe' at primary maths