Kurgan is a Turkish word for “castle” that translates as “mound,” “tumulus,” or “barrow,” a reference to the particular burial method of building mounds atop pit-graves. Kurgan culture evolved from the fifth millennia BC, from the Northern Pontic and spread across Central Europe, crossing the Dnepr and moving as far as Kazakhstan, home of the Issyk Kurgan. A practice rather than an ethnicity, kurgan culture united many of the peoples who occupied what became the Russian Empire. Scythians ae perhaps the best known who followed these burial practices because of the spectacular golden items found in many of their kurgans. The most culturally advanced kurgans are complex structures with reinforced walls and numerous internal chambers, and many still lie unexcavated across the steppes.