The Romans stationed a lieutenant and his men here “to keep the Britons in awe”. The first written reference to Machynlleth is in 1253. In the year 1291machynlleth received a royal charter to hold markets and fairs, however Machynlleths chief historical fame is its association with the welsh hero Owain Glyndwr. In 1404 he performed his first act of sovereignty by calling a parliament in the town and in 1406 he sent the famous letter to the King of France on it was his seal which has been adopted by the urban district council.
The Owain Glyndwr Institute was erected on the site of Owain Glyndwrs parliament house and is designed to resemble the building of the heros time. The parliament house proper has a fine open fireplace with recesses and is now used as a reading room and library. In the institute are the old toll tables showing the tolls payable on entering the town.
The imposing clock tower was erected in 1873 in honour of a birthday, it marks the coming of age of the then Lord Castlereagh, whose family seat was at the Plas. It was built on the site of the old market hall. The Plas was presented to the town by the 7th Lord Londonderry. The late king Edward, Queen Alexandra, King George and Queen Mary stayed here.