The upper reaches of the Mimram are crossed only occasionally by small road bridge or fords (eg at Welwyn and Codicote Bottom). Welwyn Village's three bridge are at Singlers Bridge, on the High Street (previously a ford), and on Mill Lane. The High Street and Mill Lane bridges are relatively recent, making Singlers Bridge the only early bridge within Welwyn. Singlers Bridge is named after Singlers Marsh, which was originally named Single Bridge Mead in the 18th century tithe maps, presumably acknowledging its status as accommodating the only bridge across the Mimram in the area.
