, Bulgaria. The
Falkland Islands and
Vitosha Mountain (
Bulgaria), both have an abundance of large stone runs. The highly specific combination of particular climatic conditions and rock varieties that existed there during the
Quaternary explains both the formation of stone runs in those two territories and their absence in areas with otherwise comparable nature conditions. For instance, while the present Falklands climate is quite similar to that of
Scotland, the latter was completely glacial rather than periglacial during the relevant period, which would not allow for the formation of stone runs. On the other hand, due to geological and other specifics of the southern
temperate and
sub-Antarctic territories with climatic history similar to that of the Falklands (
Prince Edward Islands,
Crozet Islands,
Kerguelen Islands,
Macquarie Island,
Campbell Islands, or nearby
Tierra del Fuego and
Patagonia), none of them features landforms comparable to the Falklands stone runs. Likewise, the specific geology of
Vitosha accounts for the fairly restricted examples of similar landforms in other
Bulgarian or indeed
Balkan mountains with comparable climatic record among which Vitosha is one of the smallest, extending just by . However, even on that small territory the stone runs exist along with
screes and other rock landforms, suggesting that the right periglacial conditions and rock composition are necessary but not sufficient conditions for the formation of stone runs. Other examples of stone runs occur in England, including at the
Stiperstones, Shropshire. They are also known in
Pennsylvania. Small examples are probably very widespread where solifluction deposits contain large concentrations of frost-resistant rock blocks. ==Falklands stone runs==