Koudelka

Location

The cut scene at the beginning of the game says that it is set in Aberystwyth in Wales. This place does exist and has a ruined castle which looks similar to the monastery in the game. However, the game states that Wales is "small country in the north of England". This is wrong in two ways - firstly Wales is a principality, which like England is part of the United Kingdom. Secondly, it's actually in the west of the UK, and borders part of the west of England - geographically they must have confused it with Scotland.

References

Koudelka features a true historical figure: the medieval Franciscan monk and savant Roger Bacon makes his appearance in the monastery graveyard.

Mystic symbols

Just a small detail: one of the FMVs of the game (the one with strange symbols floating around, when the heroes talk about alchemy and mysticism) shows circles with Hebrew words engraved: Keter, Khokhma, and Bina. Those words (meaning Crown, Wisdom, and Understanding) are the attributes of God, according to the medieval Jewish mystical teaching, the Kabbala. They actually bothered to dig up 100% authentic and rare historical/occult material.

Information also contributed by festershinetop