This is everything about the Fire Spire from Realm of the Ice Queen Page 76, which is the only source that has the Fire Spire:
"This imposing, narrow spire is still the tallest structure in Praag, despite losing its top two stories in the War. It was built as a magical college by Z'ra Rudolf II, who was fascinated by the magical arts and wished to gather all sorcerers to the city, be they ice witches, hags, or the strange wizards of the Empire. Traditionalist Ice Witches and Hags looked on in horror as, soon enough, the heights of the tower were bursting with Aethyric flames, arcs of frost-fire, and alchemical explosions, causing the townsfolk to dub it the "Fire Spire." However, the witches' vocal disapproval was soon proven wise for, during the Great War, the tower acted as a lightning rod to Chaos sorcerers and was forever twisted by Dark Magic. Now, the Fire Spire stands as a testament to the witches' warnings, for none who enter its haunted chambers return; but, even so, the promise of lost magical wonders continues to tempt desperate treasure hunters. The Fire Spire still attracts both natural and unnatural phenomena, and being near it during a storm is a very bad idea.
Although its inhabitants played a large part in defending the city during the Great War, the damage from the exploding spire and the remaining Chaos taint are forever associated with magic and its practitioners in a very negative way. Ironically, this prejudice—coupled with the large Ungol population and the risks of spellcasting (see sidebar)—means there are almost no ice witches in Praag. Hags are welcome, but none step onto its tainted soil unless they absolutely have to, leaving Praag almost entirely empty of spell casters (apart from travelling Empire wizards seeking some lost lore). But the hags know that the city is not defenceless: they can sense that some deep power, perhaps the Ancient Widow Herself, watches over the city from below, though why and to what extent remains unknown."
Anything else is Boney original.
In terms of Forests, I have to mention that Kislev has far less forests than the Empire and they don't seem as notable as the Empire's Forest monsters. Another factor to keep in mind is that the Hag Witches stayed in their lane during the Great War. Their power is attached to their environment, and many of them linger in forests, so the forests are kept safe because the Hag Witches were unaffected by the Great War.