Correct Example [#1341]

of: 209 Dense boulder field (ISOM 2017-2)
from: Tramuntana forest, Croatia

209 Dense boulder field (A)
An area which is covered with so many blocks of stone that they cannot be
marked individually and the runnability is affected.

Dense boulder field in Tramuntana forest, Cres, Croatia. Photo by: Jiří Vištejn (CC BY-SA 4.0)