Togher Historical Association: The Bog

Wednesday, September 23, 2026

The Bog - A Geological History

The Bog as of 2026

Geographically nestled in between an elongated solitary limestone outcrop to its north-east ( The Mountain ) and a cluster of same to its south ( Quarry/The Heighties ) , the Bog sat silently for thousands of years. But human interference since the 19th Century has seen to its eventual transformation and ultimately its complete erasure. This article will detail its geological history up to present times.

1830

The Bog - 1830s Map

The Bog - 1830s Ai reconstruction

The Bog - 1830s Ground Level showing spring overflowing

and willow in full bloom

The OS maps above ( 1830s ) and below ( 1880s - 1915 ) are the earliest examples of modern day mapping of The Bog. The article will treat each map with Ai to give a photo realistic view of the area from their aerial perspectives and even their ground levels. Of particular note is the changes in just a few decades! The Bog actually traverses 2 Townlands ; Clashduff and Deanrock. It was not in the classical sense of the word a true Bog but more a waterlogged wetland which acted as the Glasheen River's natural flood plain. It was fed by several underground streamlets which emanated from the high ground of Clashduff though limestone fissures. It contained a natural spring which flowed alongside an Osiery and into the nearby Glasheen River. The land itself sat 30 feet above sea level with a gently sloping gradient to its north west. In the 19th Century , the landowner in lieu of draining the Bog , had a drainage channel cut out at a downward angle to meet up with the flow of the spring and widened its natural channel to aid significantly in carrying away moisture and rainfall to free up a greater part of the Bog for grazing purposes. The spring was capped in the late 1970s and the entire Bog was leveled and covered in topsoil in the 1990s and is in use as a recreational park to date ( see below ).

1880s - 1915

The Bog - 1880 to 1915 map

The Bog - 1915 Ai reconstruction

The Bog - 1915 ground level from Summerstown Lane

Using the 1830s map ( earliest reference which will be used as a template ) as shown above , the article will now travel back Millions of years to highlight the creation of the area from its very beginnings through several important stages to bring the story up to more recent times.

Stage 1 - Ordovician Period

Stage 2 - Carboniferous Period

Stage 3 - Glacial Period ( Ice Age )

Stage 4 - Post Glacial Period

Stage 5 - Mature Prehistoric

Stage 6 - 10th Century

Stage 5 & 6 Comparison Chart

Stage 7 - 1951

The Bog - Aerial photograph 1951

The Bog - Ai reconstruction of above

The stage was set in 1967 when Cork Corporation bought up huge swathes of land in the Togher region for social housing schemes. As part of the estate of Harry Hosford , the Bog fell into this category. Deemed to be unsuitable for the construction of houses due to its waterlogged condition , it became a de facto dumping ground for builders debris. Even the once proud Clashduff House was unceremoniously bulldozed into hollows. Of course local children would use it as an adventure playground where the land alternated from swampy bog to dry mounds of earth to trees and even an open drainage channel which flowed into the nearby Glasheen River. Circa 1976 and the Corporation began the job of capping the spring and flattening the entire area and coating it with hundreds of tons of topsoil to completely change it from a local wetland to a sparse tract of open barren land. But that too would undergo a miraculous transformation in the 1980s. In the 1990s the Corporation finally began the process of turning the former historical wetland into a functioning recreational park by railing the entire perimeter and installing a football pitch , tennis court , children's playground and more recently a community garden and historical tribute peace park. It should be noted that the City Council yard is located in the corner of the former Bog next to the Glasheen River. *This will feature in a future article on this blog.