|Bridge name||Castell Cidwm Road Bridge|
|Construction No.||OB 71|
|Operational No.||OB 34.57|
|Stations | Locations | Bridges | Tunnels | Map|
The bridge was originally built by the North Wales Narrow Gauge Railways to their loading gauge. With the rebuilding of the Welsh Highland Railway the loading gauge has had to be increased to enable the use of NGG16 Garratt locomotives. To achieve this the track at Castell Cidwm (like that at other over bridges) was lowered, creating a dip under the bridge. This led to problems with flooding here. If looking carefully from the train green and red depth indicators can be observed on the bridge foundations. These tell drivers whether the depth of flood water is safe to pass or not. Recent drainage works have mitigated the flooding problems.
There is a story of long standing that nearby from Llyn Cwellyn green ladies came out of the lake, who seduced the local boys and took them back into the lake wherein, it is said, if you look over the side of a boat, you may see the boys tending the green cattle of the Lord of the Lake. To this day, if you look out on Afon Gwyrfai between Castell Cidwm and Plas y Nant, you may see from the train in the river, the green hair of the Ladies of the Lake. Please do not get out of the train to look for the green ladies; you may never come back.