An aspiration smoke detection system for detecting the presence of a fire within a region of interest. The aspiration smoke detection system includes a smoke detection unit for detecting the presence of smoke particles suspended in air; and one or more local sensors located remotely from the smoke detection unit for measuring a property of air from the region of interest that is drawn into the aspiration smoke detection system. An inlet piece includes a sensor for use with the aspiration smoke detection system is also provided. A method of detecting a fire using the aspiration smoke detection system and a method of locating a fire using the aspiration smoke detection system are also provided.