The Marrowmere is a pond that once served as a ritual site for powerful mages over a millennia ago. Whatever magics they practiced at the site have seemed to linger and spellcasters find that this latent magic can sometimes mingle with their own spells. The location is better known to locals as a boneyard due to the high number of skeletons, both recent and ancient, that have seemed to accumulate at the site and those same locals prefer to avoid the pond at all costs.
A portal was recently opened at the Marrowmere, allowing a number of creatures to escape from the Feywild into the Material Plane. These creatures terrorized to primary trade road in the region until their defeat at the hands of the guild.