During the latter Highland clearances in the 19th century, around 30,000 Gaelic speaking displaced people arrived in Glasgow looking for work. They dispersed all over the city but, usually on Saturdays, they would meet together under the railway bridge which carried the trains from Central Station across Argyle Street. Given the amount of rain Glasgow gets, the bridge soon became known as the HielanMan’s Umbrella.
The area underneath has long had problems with pollution and poor air qualiy due to the amount of traffic pouring under it. The entrance to Central Station there usually smells of piss. But I believe they have tried to tart it up since I was last there.