European Lake is a term used to describe four large lakes located in Europe. The first lake is Balaton, which is located in Hungary and is the largest lake in Central Europe. The second lake is Ladoga, located in Russia and Finland, and is the largest lake in Europe. The third lake is Onega, located in Russia, and is the second largest lake in Europe. The fourth lake is CONSTANCE, located in Germany, Austria, and Switzerland, and is the third largest lake in Europe.