Pynes Bridge, Exeter
at Upton Pyne, near Exeter.
This mid-19thC Grade II listed bridge takes Upton Pyne Hill (road) over the River Creedy, close to the A377.
The bridge has three segmental arches, and is of most unusual construction.
The unusual feature is the use of granite columns as piers. There are two groups of four Tuscan columns. Each set of columns supports four shallow cast iron arches. These in turn support stone skewbacks from which the brick courses are sprung. Because the arches are skewed, the bricks are laid in a 'spiral' pattern. The stone skewbacks are cut with a 'sawtooth' form against which the first courses of brickwork are laid.
Bill Harvey provides an excellent insight into the construction of this bridge, and points out that the masonry skewbacks are disguised to imitate the brickwork's mortar joints. See 4th and last illustrations here 
See also British Listed Buildings webpage for more information, photo, and map.
Note: It is currently (2021) not possible to get a good view of the bridge, due to the growth of trees.
Sources of Information
-  Bill Harvey Associated Ltd: Bridge of the Month No9 September 2011 - Pynes Bridge, Exeter