Recently, the explosion of the Internet of Things and the emergence of modern latency-sensitive and compute-intensive applications have posed challenges that cannot be addressed by conventional centralized cloud architectures. On the other hand, the recent developments in networking towards 5G has made fundamental changes in network architectures that increasingly generate new requirements for the cloud availability and capability at the network edge. Therefore, the conventional centralized cloud is evolving into the next-generation cloud paradigm, so-called distributed cloud. In this paper, a vision of distributed cloud is provided. We first give a precise interpretation of distributed cloud. Then, we present a representative 3-layer distributed cloud architecture and identify the key enabling technologies towards the realization of distributed cloud. We then set up a distributed cloud prototype for service deployment and discovery, and provide a preliminary evaluation of service delivery time and service response time. Finally, we highlight some open challenges and future research directions for this promising computing paradigm.