The Walpersberg is a sandstone mesa on the west bank of the Saale near Kahla in Thuringia, Germany, formed around 60 million years ago.

It is notable for formerly housing the REIMAHG-A aircraft factory, an underground facility for the production and assembly of the Messerschmitt Me 262 fighter jet during World War II.

In 1944, a construction project was commenced by Nazi Germany to convert the former sand mines at the Walpersberg to a bomb-proof underground factory for the production of the Messerschmitt Me 262.

To achieve this, the existing tunnel system was extended to 30 km by the use of over 12,000 forced labourers from Italy and Eastern Europe, and a further 3,000 skilled workers.

From 1974 until 1989, the Walpersberg was part of East Germany's Department of Defence storage complex KL-22, with ammunition, weapons, and other military supplies being stored there.