The Jewellery Quarter is an area of central Birmingham, UK, in the north-western area of Birmingham City Centre, with a population of around 19,000 people in a 1.07-square-kilometre (264-acre) area. The Jewellery Quarter is Europe's largest concentration of businesses involved in the jewellery trade, which produces 40% of all the jewellery made in the UK. It is also home to the world's largest Assay Office, which hallmarks around 12 million items a year. Historically the Jewellery Quarter has been the birthplace of many pioneering advancements in industrial technology.