Oppenheim might look like any ordinary German town. The town is some 30 miles southwest Frankfurt, and it rests along the banks of the Rhine River. But aside from the beautiful scenery at the surface, a hidden beauty can also be found under the town's narrow cobblestone streets.

According to Smithsonian, the underground tunnels found below the town has a secret labyrinth called Kellerlabyrinth that connects many cellars to houses and buildings in Oppenheim,

Only rediscovered during the 1980s because a police car sunk in that area, the Kellerlabyrinth holds the history of Oppenheim. Its network of tunnels is said to encompass about 124 miles, even though it is yet to be confirmed because others believe that some of these cellars are now connected to private homes as well. For now, only 25 miles of Kelabyrinth are allowed to the public eye via hardhat tours.

The oldest cellars in the tunnels is believed to be built sometime in 700 A.D. The cellars were first dug during the 1600s and were used as storage of food and wine. It was easier then to dig because between the years 1618 to 1614, which is the" Thirty Years War," the tunnels were also used as hiding spots from Spanish troops, Conde Nast Traveler reports.

"Since the town was completely destroyed [during the 1689 War of Palatine Succession] by order of Louis IVX of France, it went under and never recovered as a commercial town," Wilfried Hilpke, a tour guide from the Tourism Office of Oppenheim said. "No cellars were built after that time because they were not needed any longer."

In an article posted in Stars & Stripes, during World War II, some residents also took refuge in underground tunnels to hide from air raids. But shortly after, everyone again had forgotten the existence of Kellerlabyrinth.

Though these kinds of interconnected wine cellars are not new in Europe, the Kellerlabyrinth is, perhaps, the most intricate and detailed of all.