Germany - Wartburg Castle - Old postcard

Wartburg Castle was founded by Duke Ludwig of Thuringia in 1067 AD. It belonged to the landgraves of Thuringia and once hosted the medieval Minnesinger poets, immortalized by Wagner in Tannhäuser.

Most famously, the Wartburg is where Martin Luther hid out as "Knight George" upon his return from the Diet of Worms in 1521. Here he completed his translation of the Bible. During his stay here, he said he "fought the Devil with ink" and is said to have experienced dark periods of depression.

Today, the castle is a regional museum. Wartburg Castle was named a World Heritage Site by UNESCO in 1999 for its association with Luther and for its role as "a powerful symbol of German integration and unity."

Germany - Aachen

Aachen has historically been a spa city in North Rhine-Westphalia, Germany. Aachen was a favored residence of Charlemagne, and the place of coronation of the Kings of Germany.

Aachen Cathedral, also referred to as the Kaiserdom ("Imperial Cathedral") of Aachen, is a building of great historical, architectural and religious importance. Built by Charlemagne in 805 AD, its unique design was highly influential on German church architecture and it was a site of imperial coronations and pilgrimage for many centuries.

Charlemagne (Karl der Grosse in German), the first Holy Roman Emperor, began building his Palatine Chapel (palace chapel) in 786 AD. The Palatine Chapel has been described as a "masterpiece of Carolingian architecture" and was made a UNESCO World Heritage Site in 1978. It is all that remains today of Charlemagne's extensive palace complex in Aachen.

Germany – Rhein River

The Rhine is one of the longest and most important rivers in Europe (1,320 km / 820 mi).

The Rhine and the Danube formed most of the northern inland frontier of the Roman Empire and, since those days, the Rhine has been a vital, navigable waterway, and carried trade and goods deep inland. It has also served as a defensive feature and has been the basis for regional and international borders. The many castles and prehistoric fortifications along the Rhine testify to its importance as a waterway. River traffic could be stopped at these locations, usually for the purpose of collecting tolls, by the state that controlled that portion of the river.