Šumava has been a national park since 1991, and large parts of it are allowed to grow completely wild - meaning fallen trees are left where they land, new trees sprout up beside them, and no human cuts anything down. Scientists call this a 'primeval forest' and it is very rare in Europe.
The forest is full of glacial lakes - lakes that were carved out by huge glaciers during the last ice age, thousands of years ago. They are very deep and very dark. The largest, called Černé jezero (Black Lake), sits inside an almost circular rocky hollow and seems perfectly still on calm days.
Animals that have disappeared from most of Europe still live here: lynx, wolves, brown bears, black storks and white-tailed eagles all make their homes in the quietest parts of the forest. Because large areas have no roads, these animals can roam freely.
In autumn, the forests turn brilliant shades of orange, red and gold. In winter, the mountain ridges collect thick snow, and cross-country skiers trace trails through the trees. In spring, the snowmelt fills hundreds of streams with cold, clear water.