Greenhouse Effect - The Witcher 3

It turned out even the area around Kaer Morhen, a place which - one would think - Geralt knows by heart, can hide a great many interesting and undiscovered phenomena. Not far from the keep, Geralt came across an area where the weather differed remarkably from that of its surroundings. He decided to investigate what sort of forces were at work.

After a brief investigation, the witcher was able to conclude that the weather anomaly was the doing of one of the resident mages of Kaer Morhen, who had created a sort of outdoor greenhouse in which to cultivate the herbs used for the Trial of the Grasses. Though you might not know this, Geralt is quite the handyman, something which came in handy (pun unintended) at this time. He banged and nudged the broken magical apparatus and returned it to working order in no time. Before long, rare herbs were growing outside Kaer Morhen once again.