Doorways between worlds are found throughout Mid-World and Keystone Earth. These portals are found in two varieties: Magical and Mechanical. Magical doorways can be formed either from the substance of the Prim, or from the magical tension between two people. Although typically determined by the mindset of whoever enters them, these doorways could lead to unpredictable wheres and whens. Both varieties of doorways are utilized by Roland and his ka-tet, as well as their nemeses, throughout the Dark Tower universe and play pivotal roles in the stories resolution. Known magical doorways: