The 'Sandhöhlen' are a natural monument in the German state of Saxony-Anhalt. They are two sand caves known individually as the 'Große Sandhöhle' and 'Kleine Sandhöhle'. The caves are located in a wooded area called im Heers below the fortress and crags of Regenstein north of the town of Blankenburg. It is surmised that a Germanic thingstead was held here in protohistoric times.