At the heart of the Altai Mountains in Russia, a mysterious ancient culture has created megaliths in shape of mythical creatures – a dragon and a griffin.

Russian archaeologist Ruslan Posyolkov discovered the impressive structures in 2013 while surveying mountains, the Siberian Times reports.

He believes the megaliths date back at least 12,000 years, and could thus have been created by prehistoric people at the end of the last Ice Age.

Analyses of the samples will nevertheless have to be conducted in order to verify this hypothesis.

The dragon megalith is estimated to weigh a staggering 120 tons. "It has bold and smooth features similar to those of crocodiles and dinosaurs, impossible to form if granite cracks naturally", Peresyolkov noted. "If we accept the fact that the dragon is an artificial object, then the stones composing it were brought, processed and installed in a certain position".

Detailed observations have revealed that the dragon is composed of six granite rocks in all, with sizes varying from 1.3 to 2.1 metres in length).

This could be the oldest known representation of the fantastical beast in Siberia.

The researcher also gives a detailed description of the ''griffin megalith'', which looks the eagle-headed mythical creatures frequently depicted by the Scythian culture which lived north of the Black Sea and in the Eurasian steppes sometime between 2,000 and 3,000 years ago.

However, the structure appears to be much older. Measuring nearly 6 metres in length and 2.5 metres in height, the griffin is here characterised by a reptile-like head and a heavy beak.

Many interrogations remain about who the people who created these massive structures were and what purpose the megaliths served. Posyolkov's findings have yet to be verified by other scientists and published in a peer-reviewed scientific journal.