Until the 9th century, various linguistic landscapes were formed out of older Germanic languages in the eastern part of the Frankish Empire. The area of Hamburg's Old Town was visited sporadically since the Neolithic period. Archaeologists have no traces of a permanent settlement in the form of foundations, rubbish pits, or gravesites so far. Until now several stone tools and fragments of pottery were the only finds. In the wider metropolitan area of Hamburg however, archaeologists have found various settlements and cemeteries from all prehistoric periods since the end of the ice age. Although many archaeological traces were destroyed when the modern metropolis developed, Hamburg's ground still holds a few surprises, even under the asphalt streets. This includes the discovery of the fortification Hammaburg, which was known from early documents. Archaeological excavations in the Cathedral Square (Domplatz) could even prove the existence of a previous building in the Saxon style, dating back to the 8th century.