The massive remains of an ancient wall in the city of Cologne were first unearthed a year ago during construction work for a new Protestant church community center.

While it was clear from the start that the wall was of Roman origin, it was initially believed to be the ruins of a public assembly room. But what stumped experts were "unusual, niche-like divisions" in the wall, says Cologne historic preservation official Marcus Trier.

After comparing the structure with other ancient buildings, including the Roman city of Ephesus in present-day Turkey that had a monumental library, it turned out that the remains in Cologne belonged to a library built in the 2nd century in the then-Roman city.

From baroque to modern: Germany's most impressive libraries Stuttgart's municipal library Designed to be an intellectual and cultural center, the new Stuttgart municipal library was built in 2011, a towering nine-story cube. Outside, it's constructed of pale gray concrete framing glass bricks. Inside, it's stark white. Books that line the walls of the light-flooded five-story gallery hall are the only splashes of color. At night, the library is illuminated in different colors.

From baroque to modern: Germany's most impressive libraries Duchess Anna Amalia library The Duchess Anna Amalia Library is a small gem in Weimar that houses books, maps, musical scripts and ancestral registers. It's named after the duchess who saw to it that the court's book collection was moved into the Rococo library in 1766. A fire in 2004 destroyed part of the precious collection. After undergoing restoration, the UNESCO-listed building reopened three years later.

From baroque to modern: Germany's most impressive libraries Herzog August Library Bibliotheca Augusta, the Herzog August Library in Wolfenbüttel, is one of the oldest libraries in the world that has made it to the present day without losses to its famous collections. An avid book collector, Duke August (1579-1666) made it one of the largest European libraries of his day. Scholars continue to turn to the library for its wealth of medieval literature.

From baroque to modern: Germany's most impressive libraries Foster Library Due to its cranial shape, this library in Berlin has been dubbed "The Brain." It houses the libraries for the philosophy and humanities departments at the capital's Freie Universität and has quickly become an architectural landmark. It was designed by internationally renowned architect Norman Foster and opened in 2005.

From baroque to modern: Germany's most impressive libraries Oberlausitz Library of Sciences The Oberlausitz Library of Sciences in Görlitz, right on the border with Poland, dates back to 1806. Plain but inviting, it is one of the most striking early classicist library halls. More than 140,000 books document the history, culture, nature and society of the region between Dresden to the West and Wroclaw to the East.

From baroque to modern: Germany's most impressive libraries Jacob and Wilhelm Grimm Center The spectacular Grimm Center is a part of Berlin's Humboldt University. Built in 2009, it houses a library and the university's computer and media services. The reading room, above, is at the heart of the building. It gives people "a sense of the outdoors" through its size and tiered, almost scenic design, says architect Max Dudler. It offers "the feeling of reading under the open sky."

From baroque to modern: Germany's most impressive libraries Bavarian State Library Collections begun in the mid-16th century have grown to more 10 million books in the Bavarian State Library in Munich, once known as the Bibliotheca Regia Monacensis. The collections found a home in the current building between 1832 and 1843, which was almost completely destroyed during World War II. The library took years to rebuild. Author: Dagmar Breitenbach



The original building was probably two stories tall, with a size of around 20 by 9 meters — an extension was later added. Scholars and researchers would have enjoyed a lot of choice, Trier says, with "certainly several thousand scrolls to borrow."

The remains of the ancient library are to be integrated into the new church building, with part of the wall being made accessible to visitors. Other parts of the excavation will be preserved to give access to future generations of archaeologists.

Read more: Nazi-looted books found in German libraries

The western German city on the Rhine River is known worldwide for its magnificent Gothic cathedral; however Cologne is also rich in Roman history.

A walk through a part of the old Roman sewer system is an unusual experience

A Roman general established an urban settlement called Ara Ubiorum in the Cologne area in 38 BC. The military outpost flourished and was given colony status by Emperor Claudius several decades later.

Claudius renamed it Colonia Claudia Ara Agrippinensium, or CCAA for short, after his wife Agrippina the Younger who was born there.

From walls, city gates and aqueducts above ground, to delicate mosaics and historic sewer canals below ground, a newly found library is set to become a significant part of Cologne's, and Germany's, ancient Roman heritage.

