Menai Bridge is at the narrowest point on the banks of the Menai Straits, the stretch of water which separates the island of Anglesey from the mainland. From ancient times, this was the main point of contact between the two shores. Routes fanned out to the other corners of the island – Amlwch, Beaumaris and Holyhead with its links to Ireland. This area then became the gateway to the island of Anglesey or Ynys Mon.

The speed of the water in the Straits has always made boat crossings dangerous especially through the Swellies which is the most turbulent stretch of water in the area. The Menai Suspension Bridge was built at this narrow point by Thomas Telford in 1826 and, at the southern end of the Swellies, the Brittania tubular railway bridge was built by Robert Stephenson in 1850.