From-

     William Roy's maps       1740s

     John Adair's maps         1680s

     Joan Blaeu's maps         1640s

     Timothy Pont's maps    1590s

A modern O.S. map is used to display the data : location, water-way, historical notes, architectural style, recorded age, current structural age, links, photographs, map sources and OS coordinates.

The catalogue has more than 600 bridges.  Some no longer exist; some are in ruins; the majority have been rebuilt in a more modern style.  Thirty per-cent do still exist, however, substantially as they were created (red and maroon markers in the catalogue).  These are beautiful monuments in the landscape - architectural treasures, often ignored and sometimes neglected.