Prague Old Jewish cemetery
There is the oldest Jewish cemetery in Prague and it is believed, that it is also the oldest Jewish cemetery in whole Europe. It was used in 15th century for more than 300 years. As there were many Jews living in the Jewish quarter, there was also high demand for places at the cemetery, but the area was limited - the graves had to be made in several layers - there are areas with even 12 layers of graves!
For more information you can visit Old Jewish Cemetery website