The next generation of wireless systems will employ networking equipment mounted on mobile platforms, unmanned air vehicles (UAV), and low-orbit satellites. As a result, the topology of 6G wireless technology will extend to 3D vertical networking. With its extended service, 6G will also give rise to new challenges which include the introduction of reconfigurable intelligent surfaces (RIS), the mmWave spectrum, the employment of massive MIMO systems, and the agility of networks. One of the key elements of 6G technology is the need for accurate sensing and positioning. The emergence of new research activities in Integrated Sensing and Communication (ISAC) is to find answers to some of these open and important problems. In this talk, we will discuss how sensing and positioning can be a key enabler of 6G, and what challenges the next generation localization technology will face when integrated into the new wireless networks.