Between 1890 to 1896 three tunnels each 5m in diameter, were dug beneath the Clyde between Tunnel Street in Finnieston and Mavisbank Quay for the Glasgow Harbour Tunnel Company. One was reserved for pedestrians while the other two below carried north- and southbound horse-drawn vehicles.
The Rotundas featured winding gear to raise and lower giant lifts which could accommodate the horses.
The pedestrian tunnel closed in 1980 and the cart tunnels were eventually filled in in 1986.
The North Rotunda now operates as a restaurant, but the one above, despite being used during the 1988 Garden Festival, now lies empty.