What country's capital is a natural stronghold at the conjunction of the Alzette and Petrusse rivers and is home to the European Court of Justice?

The European Court of Justice, known formally as The Court of Justice of the European Communities, is analogous to the U.S. Supreme Court in that it is the highest court of appeal over matters of EU law and its application. In order to ensure fairness, the Court seats one Justice from each of the 27 member nations.

The ECJ was authorized by the 1951 Treaty of Paris, and was established in Luxembourg, Luxembourg, in 1952.