Crannogs are places of habitation, constructed as small artifical islands in shallow lakes or even in coastal waters. They were built using whatever material that was to hand, but typically rocks, earth, gravel and brushwood were thrown down into the water to create a platform. Very often, the crannog was built by driving a palisade of timber stakes into the lake bed to surrond and hold the infill material in place. This platform, having become consolidated was used to build a dwelling on, with perhaps some animal accommodation attached. Buildings were mostly of timber but some were of stone and there are instances of tower houses being erected on crannogs. It was usual to have a second palisade of timber stakes up on the crannog and surrounding the building.
Because crannogs were wetland habititions, preservation of organic material associated with them is generally good. This means that timbers found on such sites can be dated accurately using dendrochronology. In addition it is possible to construct a very comprehensite picture of crannog functions and lives of their inhabitants. Many crannogs have been excavated over the years, all of them in sites that have been drained artifically. The crannog at The Rise has not yet been excavated.
The evidence seen in the mound at Loughmerans (The Rise) is very compelling for the existance of a crannog. From an earth science viewpoint it can be stated with certaintly that the mound is not a natural occurrence. The existance of a crannog is the alternative possibility and this is supported by archaeological opinion. The partially decayed wood found both on the mound and at its outer circumference could possibly be explained by the existance at one time of timber construction – either as dewllings or as palisades, on the mound. While the composition of the mound can only be guessed at from the cursory examination given, it seems likely that it is mostly of gravel. This would be consistent with findings in other crannogs and the Loughmerans area is currently dotted with gravel workings, many of which are still in use.