A compelling property of virtual reality is that it allows users to interact with objects as they would in the real world. However, such interactions are limited to space within reach. We present Poros, a system that allows users to rearrange space. After marking a portion of space, the distant marked space is mirrored in a nearby proxy. Thereby, users can arrange what is within their reachable space, making it easy to interact with multiple distant spaces as well as nearby objects. Proxies themselves become part of the scene and can be moved, rotated, scaled, or anchored to other objects. Furthermore, they can be used in a set of higher-level interactions such as alignment and action duplication. We show how Poros enables a variety of tasks and applications and also validate its effectiveness through an expert evaluation.