The Kölner Dom - Cologne Cathedral - is a Gothic masterpiece and Germany's most visited landmark, drawing over six million visitors a year. Construction began in 1248 and was only completed in 1880, making it one of the longest building projects in history. The main entrance (Haupteingang) faces the Domplatte square opposite the central station. The cathedral is a UNESCO World Heritage Site and regularly hosts concerts, services, and major public events.