Series "Small Worlds" Part 4 - Scotland: The Sheep of North Ronaldsay Island - The natives of North Ronaldsay were always a bit unusual. Until the 19th century they still spoke a dialect of Old Norse, a language that had already died out on the neighboring islands. About 600 people once lived on North Ronaldsay. Nowadays the number of inhabitants is tiny. Life on the northernmost of the Orkney Islands was just too harsh on the human population. The native breed of sheep, however, which feed mainly on marine algae, could now become a lucrative source of income. But new farmers are having a hard time finding land while native residents are loath to give up their property. Poland: Counting the costs of EURO 2012 - Since it co-hosted the UEFA European Football Championship last summer, Poland has 1000 new kilometers of motorways and new stadiums in Gdansk, Wroclaw and Poznan. But now, six months later, debt levels are rising. In Gdansk the stadium has already run up millions in debt for its operators. The Wroclaw stadium is so deep in debt that the electricity was almost turned off. Poland had invested some 200 billion euros in preparing for EURO 2012. That has yet to pay off. The country had hoped the new sport venues would attract additional tourists, but so far that has not been the case. Bulgaria: Party Zone amid Gray Housing Projects - Pulsating beats till the early morning hours: that's Studentski Grad. Students have breathed new life into a communist-era high rise district in southern Sofia. Nowhere else in Bulgaria's capital is living space so cheap and that has attracted many university students. But what was initially viewed positively as the revival of a district now has clear disadvantages for residents because students like to party. More and more clubs are springing up and there's occasional trouble with the police. Sofia's municipal leaders don't want to see the entire district turning into a party zone and are now threatening to impose curfews. France: The Invisible Threat - French security services fear retaliatory attacks from Islamist terrorists following the country's military intervention in Mali. The threat is not only confined to people with Arab roots. Security experts are warning that danger could also come from French converts to Islam. Meanwhile the Malian community remains complacent. Although Malians in France often live in extremely humble circumstances, they welcome the French military mission in their home country.