Rivers divide people, bridges bring them together: For almost 500 years, the old Bridge of Mostar connected the lives of Christians and Muslims in an ancient town between the Balkans and Europe.

To many, this masterpiece of mediaeval masonry was as important as the leaning tower of Pisa or the Acropolis in Athens. Built to equal halves by Muslim and Christian craftsmen, the highest and biggest stone-arch of its time stood as a symbol of understanding between cultures.

Then came November 9, 1993: When war tore former Yugoslavia apart, the age-old bridge was destroyed by Croatian artillery. It left a wound that has not healed to the present day.

Now, an international team is aiming to reconstruct the bridge. Success is all but certain. Many of the old bridge-builders' secrets have long been lost: How did they create a mortar that was much harder than any mixture known today? And how did they build a bridge that lasted 500 years with stones that today's experts find not strong enough?

With underwater diving sequences, computer animation and professional re-enactment, we tell an adventure between archaeology, history and current politics.