Cotdû
A mountain range in the south of Russia.
In Parzival, Wolfram includes a mention of the Caucasus as the location of the Grail Castle, also known as the Castle of the Grail or Munsalvasche. This is the dwelling place of the Fisher King, the wounded guardian of the Holy Grail.
“The Grail, it dwells in a castle
Der Grâl, er weilet in einer Burg
In der 'Cotdû' heißet sie,
Sô rîchelîch und sô vreudeclîch
Grâlburg nâht niemen mê.
Called ‘Cotdû,’
So richly and so joyously,
No one knows the Grail Castle more.“
The term Cotdû is often associated with the Caucasus, although the exact location and identification of this castle remain subjects of scholarly debate.
Source
Parzival | Wolfram von Eschenbach, 1200–1210