Lackenberg, Mountain summit in Šumava National Park, Czech Republic.

Lackenberg is a mountain summit in the Šumava range located at the border between Czech Republic and Germany. Dense forest surrounds the peak, and from the top you can see far across the landscape toward both countries.

The flat summit lies on the border between Germany and the Czech Republic, which runs across its highest point. On the German side it sits at the northern edge of the Bavarian Forest National Park. The border along the ridge was part of the Iron Curtain until 1990, when the restricted zone made the approach dangerous.

The name Lackenberg also belongs to the Laka (Lackensee) cirque lake on the north side, the smallest and highest of the five Bohemian Forest cirque lakes. The Czech name Plesná and the German Lackenberg denote the same summit; the variant Debrník appears only on a 1:5,000 state map of 2003 and in the 2006 Zeměpisný lexikon ČR.

No marked hiking trail leads to the summit, and the Czech side lies in the "Plesná a Poledník" zone of Šumava National Park, where entry is allowed only on marked trails, so the peak is inaccessible from the Czech Republic. Ascents are made from the German side, either on the long route from Zwieslerwaldhaus via the Ruckowitzschachten or along the border, which was dangerous because of the Iron Curtain until 1990.

The summit is a flat, boggy meadow with no rock, summit cross or view, so even locals rarely climb it. The usual routes run from Zwieslerwaldhaus via the Ruckowitzschachten or along the border, which was dangerous because of the Iron Curtain until 1990.