The Menai Suspension Bridge is a suspension bridge between the island of Anglesey and the mainland of Wales.

Prior to the bridge's completion in 1826 the island had no connection to the mainland, and all movement to and from Anglesey was by ferry. However, the Act of Union 1800 increased the need for transport to Ireland, and with Holyhead as one of the principal terminals to Dublin it was decided that a bridge was needed.

Thomas Telford was assigned the task of improving the route from London to Holyhead, and one of the key improvements was his design of the suspension bridge over the Menai Strait between a point near Bangor on the mainland and what was then the village of Porthaethwy which is now also known as Menai Bridge on Anglesey. The design of the bridge had to allow sailing ships 100ft tall to pass under the deck at high water slack tide.

Construction of the bridge began in 1819 with the concrete towers on either side of the strait. Then came the sixteen huge chain cables, each made of 935 iron bars that support the 176 metre span. To avoid rusting, each cable was first soaked in linseed oil. The bridge was opened to much fanfare on January 30 1826, and succeeded in reducing the 36 hour journey time from London to Holyhead by 9 hours. The bridge was not the first suspension bridge, but was so hugely greater than anything previously built that it is considered the world's first modern suspension bridge.

Damaged by winds in 1839, the road surface needed extensive repair, and in 1893 the entire wooden surface was replaced with a steel deck. Over the years, the 4.5 ton weight limit proved problematic for the increasing freight industry and in 1938 the original iron chains were replaced with steel ones without the need to close the bridge. In 1999 the bridge was again closed for around a month to resurface the road and strengthen the structure, requiring all traffic to cross via the nearby Britannia Bridge.

On February 29 2005 the bridge was promoted to UNESCO as a candidate World Heritage Site and coincidentally on the same day one carriageway of the bridge was closed for six months restricting trafiic to a single carriageway so that traffic now only travels south in the morning and north in the afternoon.

The bridge has a memorial to the Aberfan disaster victims on the Anglesey side

Quote

White Knight says to Alice,
'I heard him then, for I had just completed my design,
To keep the Menai Bridge from rust
By boiling it in wine.'
 Through the Looking-Glass, Lewis Carrol