summary:A quotation is from a Czech lyrical poem by J. V. Sladek: “I know a crystalline fountain on the deepest spot of a forest” (“where there is the deepest forest”). This article conduces to the mathematisation of the problem of the forest depth (i.e. the central point of a forest). It defines this depth (the central point) in a konvex polygon and introduces the term “enteron” for this “deepest” point
