The Forth Bridge is a historic railway bridge spanning the Firth of Forth between South Queensferry and North Queensferry in Scotland. Connecting the Lothian region and the Fife region, it is a marvel of Victorian engineering. Designed by Sir John Fowler and Sir Benjamin Baker for the North British Railway, the cantilever bridge was completed in 1890 and quickly became an iconic symbol of Scotland and the Industrial Revolution. A World Heritage Site since 2015, the bridge is also a Category A listed building. At 2.5 kilometers long, the Forth Bridge is the longest cantilever bridge in the world. It also has a remarkable open-air gallery underneath that allows visitors to experience the engineering and architectural details of the bridge up close.