Luxembourg, also known as Luxembourg City, is the capital city of the Grand Duchy of Luxembourg (also named "Luxembourg"), and the country's most populous commune. Standing at the confluence of the Alzette and Pétrusse rivers in southern Luxembourg, the city lies at the heart of Western Europe, situated 213 km (132 mi) by road from Brussels, 372 km (231 mi) from Paris, and 209 km (130 mi) from Cologne. The city contains Luxembourg Castle, established by the Franks in the Early Middle Ages, around which a settlement developed.
As of January 2016, the commune had a population of 115,227, which was more than three times the population of the country's second most populous commune (Esch-sur-Alzette). The city's metropolitan population, including that of surrounding communes of Hesperange, Sandweiler, Strassen, and Walferdange, reaches 180,000.
In 2011, Luxembourg was ranked as having the second highest per capita GDP in the world at $80,119 (PPP), with the city having developed into a banking and administrative centre. In the 2011 Mercer worldwide survey of 221 cities, Luxembourg was placed first for personal safety while it was ranked 19th for quality of living. It is a seat of several institutions of the European Union, including the European Court of Justice, the European Court of Auditors, the Secretariat of the European Parliament, the European Investment Bank, the European Investment Fund, and the European Stability Mechanism.