Craig Liath (also known as Grey Rock) is the home of the goddess Aibell in Ireland.
Walter Peck dispatched Kylie Griffin and Peter Venkman to find Aibell and request she lift the curse on his friend Una O'Neill. Kylie relied on the extensive lore surrounding Aibell's home and a pair of Ecto Goggles. She located the entrance and to Peter's surprise, Craig Liath appeared to them. Throwing caution to the wind, they ventured inside. Peter started to notice the cave was getting brighter and brighter. Aibell confirmed as much. Peter turned and fired at her. Aibell showed herself and was annoyed with being shot at by intruders but admired their boldness. She inquired what they wanted. Kylie and Peter stated their case. Eventually, Aibell remembered who Una was and told them about the crime she committed over 500 years ago, breaking the heart of a man who was under her protection. Aibell was intrigued and proposed to abandon her claim in exchange for a favor, a bit of consideration in the future. Peter agreed to the deal before Kylie could stop him. Aibell teleported herself, Peter, and Kylie back to Una's property.
Aibell sensed the power of the Rauoskinna after the Ghostbusters were accidentally teleported to Hell. As they journeyed through Hell to find a way out, Aibell teleported them to Craig Liath and called in the favor Peter owed her. She asked for the Rauoskinna. Janine Melnitz refused to turn it over until they made sure they was nothing that could be used to bring back Egon Spengler. As a sign of good faith, Aibell used her own power to bring Egon back to life. Peter handed the Rauoskinna to her but Jenny Moran destroyed it with her Particle Thrower. Aibell was infuriated and Jenny was vaporized. Peter caught her on a technicality since he complied with her. She was at a loss and angrily teleported them all back to Central Park.
Based on Mythology
According to Irish mythology, it is said Aibell dwells in a silent glen at Craig Liath, the "Grey Rock," two miles north of Killaloe.