Transformation Mansion

For what seems like generations a lavish mansion has sat atop a hill on the edge of your town, none seem to enter and none seems to leave despite being well maintained and many remembering meeting those that lived and worked in the mansion. Somehow you have gained access to the mansion and have set out to explore the mansion unaware that the mansion is a focal point for magic and all it takes is one misstep to have all that you know changed.