amazon.co.uk] is my favourite.
In her introductory essay, Nelson discusses the three basic types of bridge: beam bridge, arch bridge, and suspension bridge. It seems to me that the remainder of the book then goes on to comprehensively demonstrate how futile such simple categorisations can be.
The book is a product of the author's own extensive explorations of the Scottish Highlands, and documents a truly fabulous variety of bridges both historic and modern. It is arranged geographically, so that, for example, all the bridges of Lower Speyside form a chapter. Each bridge is given a map reference, and, where necessary, directions by which to find it. The text combines factual details on the nature and history of the bridges with the author's own opinions, and there are a good number of photographs.
These may seem like the basic essentials for any guidebook, but it is amazing how few books in this field manage to do such a good job. Highland Bridges is both reasonably comprehensive, detailed and yet highly readable. It is a friendly book, suitable for readers both lay and expert, and of the type that makes you immediately wish to plan a bridge-viewing journey.
This book introduced me to a number of bridges which I would not otherwise have encountered, mostly notably the astonishing Craigmin Bridge, but also the beautiful Maryhill House footbridge. Its coverage is generally excellent, with both the famous and the unknown given equal space.
What jumps out at me the most is the sheer variety of types of bridges to be found in the Scottish Highlands. There are many beautiful stone arches and quite a few charming suspension bridges, but also a staggering range of oddities, such as the fortress-like concrete Findhorn Bridge; the intricate Dredge designs at Whin Park and Bridge of Oich; rare timber trestles at Broomhill and Aultnaslanach; and much, much more. I think there are few areas of the United Kingdom so well equipped with such fascinating, intriguing and bizarre bridges.