Monistic substantivalists believe that material objects and regions of space-time are not two distinct kinds of fundamental of entities. For the monist, objects either are identical with regions or are somehow derivative from them. Dualistic substantivalists view regions and objects as distinct kinds of fundamental entities. One virtue monists claim over dualists is that their view is more ideologically parsimonious than dualism because monists can do without a primitive notion of location. In this paper I provide an argument that undercuts some of the theoretical edge that monists claim over dualists. The assumption that the monist can provide a reduction of location unique to her position rests on a false assumption about the possible structures spacetime can have. If it is metaphysically possible for two distinct regions to coincide with respect to all their significant spatiotemporal properties and relations (call these 'coincident regions'), then analyses of location unique to monism will turn out to be inadequate. / Master of Arts / You, I, a rock on the ground, electrons, and galaxies all have something in common: we are all material objects. Material objects are often defined as the things that have locations within spacetime. But what is it to have a location within spacetime? Some authors, monists, believe that to have a location in spacetime is to be no more than a bit of the spatiotemporal manifold. Others, dualists, think of spacetime like a box that objects get placed into. For them having a location is to “take up” part of the room in this box. As the debate currently stands, many philosophical considerations look to point in favor of monism over dualism. In this paper I discuss a novel argument that this assessment does not stand up to scrutiny. The argument makes use of contemporary theories in physics and advanced geometry to argue that distinct parts of spacetime can be located at one another. This is shown to undermine many of the considerations which are thought to favor monism over dualism.