Aachen is a city in western Germany, located near the borders of Belgium and the Netherlands. It is known for its rich history and was once the favored residence of Charlemagne, the first Holy Roman Emperor. The city's most famous landmark is the Aachen Cathedral, a UNESCO World Heritage site, which houses the Palatine Chapel built by Charlemagne in the 9th century. Aachen is also recognized for its thermal springs, which have been used for their healing properties since Roman times. The city hosts the annual Aachen International Horse Show, attracting equestrian enthusiasts from around the world. Additionally, Aachen is home to the RWTH Aachen University, one of Germany's leading technical universities.