Beyond the answers - interesting background to this quiz

A river that crosses borders without asking permission

The Rhine rises in the Swiss Alps and empties into the North Sea, passing through six countries along the way. That makes it one of Europe's most international waterways, and for centuries it has carried freight, travellers and ideas between the Alps and the coast. Its banks are lined with castles, vineyards and industrial ports, a mix that says a lot about how Europe uses its rivers.

A citadel the Spanish never found

Machu Picchu sits high in the Andes in Peru, built by the Inca in the fifteenth century and abandoned not long after the Spanish conquest. Because the site was never discovered by the conquistadors, it escaped the destruction that levelled many other Inca settlements. It remained largely unknown to the outside world until the early twentieth century, when it was brought to international attention.

A director who knew exactly when to frighten

Alfred Hitchcock released Psycho in 1960, at a point in his career when he was already famous for suspense films. The movie became notorious for its shocking shower scene and for the bold decision to kill off a leading character early on. Its influence on later thrillers and horror films is hard to overstate.

Where three great mountain ranges meet

The Pamir Mountains stretch across Tajikistan, Afghanistan and China, often described as a knot where the Himalayas, Karakoram and Hindu Kush converge. The region is remote and sparsely populated, and parts of it sit above 7,000 metres. For centuries it formed a crucial section of the Silk Road, linking traders travelling between China and Central Asia.