Beyond the answers - interesting background to this quiz

The port city that changed hands seven times

Rijeka sits on the Kvarner Gulf, an inlet of the Adriatic Sea, and its position has made it a prize for empires rather than a quiet harbour. Over the centuries the city passed between the Habsburgs, the Kingdom of Italy, Yugoslavia and finally Croatia, and it still carries a distinctly Central European feel alongside its Mediterranean one. Its name means "river" in Croatian, a reference to the Rjecina, which cuts through the city before reaching the sea.

The skin you live in

Skin is the body's largest organ by both weight and surface area, and it is far busier than its calm exterior suggests. It regulates temperature through sweating and blood flow, blocks much of the ultraviolet light that would otherwise damage deeper tissue, and houses the nerve endings that let you feel texture and temperature. It also renews itself constantly, shedding older cells as new ones form beneath.

A river that feeds millions

The Mekong begins on the Tibetan Plateau and runs through China, Myanmar, Laos, Thailand, Cambodia and Vietnam before emptying into the South China Sea through a vast delta. That lower basin is one of the most productive agricultural regions in the world, and its fisheries support a large share of the protein eaten across Southeast Asia. The river's seasonal rise and fall shapes rice planting, fishing calendars and the daily rhythm of entire communities.

The isthmus that links two continents

Guatemala occupies a stretch of Central America that borders Mexico to the north and Honduras to the east, making it a natural crossroads between North and South America. Its landscape packs volcanoes, highlands and tropical lowlands into a relatively small area, and it was the heartland of Maya civilisation, whose cities still stand in the northern Peten region. That combination of position and terrain has shaped everything from trade routes to the country's remarkable linguistic diversity.