Knug (pronounced K'noogh) is a giant cave underneath Dark Keigan that stretches north away from Acrityrda. Knug have been discovered through years of archeological prospecting through the passages of Acrityrda. It has since then barely been fully explored due to the psychological discomfort that starts to occur when someone travels far into the cave.
The cave doesn't seem to have been formed through natural processes. Through radar probing, the cave appears to be a long singular tube that stretches for about 30 kilometers. The cave is littered with plants that are similar to the ones in Luobnyka. But the huge root-like structures are completely new to science. The walls of the cave is made up of knugian wood, which is a mutated form of acrityrdian wood that have been altered by nyka cells that originate from Luobnyka.