Three Trout Stream: “Three Trout” is possibly a corruption of “trí droichead”, Three Bridges. Thousands of years ago ice spreading from North of the Firth of Clyde over the country east of the Dublin and Wicklow mountains, formed large lakes. Some of the melt water flowed down the valley from the Glen of the Downs to Delgany.
A small lake was formed which later became a stream – Three Trout Stream. It flows along the glen, under Barry’s Bridge and meanders onwards under 3 bridges, through Charlesland to the sea