28 May 2018
|Date||14 February 2015|
|Location||Port Penrhyn, Bangor||SH 59229 72579; 53.23152°N, 4.11044°W|
The weir on the Afon Cegin at Port Penrhyn replaced earlier wooden lock gates that were used to control the level of the river at low tide. Slate vessels using the port formerly moored in an upstream basin in the river, access to which would have become restricted when the bridges were built.