Rozrog is a fortress in Verden, a kingdom which borders Cintra. The fortified city is at the mouth of the mighty Yaruga. Nearby are the fortresses of Bodrog and Nastrog. The Yaruga river itself forms a natural border with neighboring Cintra.
"If they have truly learned anything", Henselt shrugged, "they will not cross the Yaruga. The river estuary on the border between Cintra and Verden is still controlled by Ervyll and his three strongholds: Nastrog, Rozrog and Bodrog. They cannot be seized just like that — no new technology is going to help them there."
- - pg.215, Blood of Elves (UK edition)
Rozrog stands as the legacy of actions taken by the elves during the Time of Contempt.
Something ends, Something begins non-canon short story Edit
The castle apparently now the property of a certain former king Herwig, serves as the setting for Geralt and Yennefer's wedding. Galahad mistakes the ruins for Montsalvat, but Dandelion asserts that they are not in Avalon, but Schwemmland, which translates roughly to "marshes".
It is described as a shapeless heap of stones in a dire need of general repair, standing on a cape in the middle of the lake.
Rozrog is mentioned as half-ruined, but still usable stronghold.