Slough is a large town in Berkshire, England, west of central London, north of Windsor, east of Maidenhead, south-east of High Wycombe and north-east of Reading. Sitting at the gateway between the Thames Valley and London and at the intersection of the M4, M40 and M25 motorways, it offers easy road access to the rest of the UK. The A4 and the Great Western Main Line pass through the town, which was historically part of neighbouring Buckinghamshire. From 2019 the Elizabeth Line will allow fast journeys to the heart of London, whilst from 2021 the Western Rail Link cut journey times to Heathrow Airport to just seven minutes. As of 2011 Sloughs population was one of the most ethnically diverse in the United Kingdom. Slough has the highest concentration of global corporate HQs outside London. Slough is home to the Slough Trading Estate, wholly owned and managed by SEGRO, and the largest industrial estate in single private ownership in Europe.