The northern Gibraltar — medieval casemates, EU institutions and deep gorge valleys in the city centre
Luxembourg City is the capital of the Grand Duchy of Luxembourg, a small landlocked country between France, Germany, and Belgium. The city is dramatically bisected by two river gorges (the Alzette and Pétrusse valleys) that create a natural moat — the reason Luxembourg was one of Europe's most powerful fortresses for 400 years. The Bock Casemates (17km of underground tunnels carved into the cliff) once housed 35,000 soldiers and cannons pointed in every direction. The Grund quarter at the bottom of the gorge is a village of whitewashed cottages and cobbled streets directly below the Old Town…
Count Siegfried of the Ardennes built a fortified castle on the Bock promontory in 963 AD, starting a fortress city that every major European power would fight over for the next nine centuries — it was besieged or occupied by Burgundy, Spain, France, Austria, and Prussia at various times. The 1867 Treaty of London declared Luxembourg perpetually neutral and required the demolition of its massive fortress walls; the demolition took 16 years and removed 40,000 tonnes of stone from what had been called 'the Gibraltar of the North.' The Bock Casemates are what remained — 17km of underground galle…