There are a number of crypts in The Witcher, here is a list of them:
Crypt name Location Ancient crypts Swamp cemetery Cemetery crypt Cemetery Crypt in the outskirts Outskirts, north-east Crypt at the Lakeside Lakeside near Murky Waters Crypt in the fields Fields near Murky Waters Crypt in the sewers Sewers Lionhead Spider Cultists' lair Sewers Raven's crypt Swamp cemetery, east Striga's crypt Swamp cemetery, on the island
Additionally, some sarcophagi are referred to as "crypts", adding to the general confusion.