We come at last to the Danube, and to one of the most magnificent castle-scapes in all of Europe. High on Castle Hill, above the great river that divides Budapest

Above the rooftops and the winding river of Prague, on a long ridge crowned by the soaring spires of a great cathedral, spreads one of the most extraordinary royal complexes

There is a photograph of Burg Eltz that almost everyone has seen, even if they have never heard its name. A cluster of pale towers and steep grey roofs rising

In the far south of Albania, on a wooded peninsula between a shining lagoon and the channel that separates the mainland from the Greek island of Corfu, lie the ruins

Most castles are square, or round, or a sprawl of walls following the shape of a rock. Caerlaverock is a triangle. Rising from the flat, marshy land near the Solway

Most castles were built to keep enemies out. Caernarfon was built to keep a whole nation down. When Edward I of England finally crushed the independent princes of Wales in

Some castles guard a hill, some a river crossing, some a coast. Caerphilly guards itself with water, and lots of it. Spread across a series of great artificial lakes in

Rising from a rocky island in the middle of the River Suir, in the green county of Tipperary, Cahir Castle is one of the largest, strongest, and best-preserved medieval castles

Cahokia was the largest pre-Columbian city in North America, a Mississippian settlement in Illinois built around a massive earthen pyramid called Monks Mound.

Deep in the rainforest of southern Mexico, close to the border with Guatemala, lie the ruins of Calakmul, one of the two great superpowers of the Classic Maya world. Its