Slovakia

The largest and deepest lake in Slovakia is Veľké Hincovo pleso - a Tatra pond located in the Hincovo Valley, which is the upper part of the Mengusovská Valley in the Slovak part of the High Tatras.

An excerpt from the article 37 facts about Slovakia

The natural lakes of Slovakia are large lakes of glacial origin, which were formed as a result of the retreat of the ice sheet.