Cooleeny townland contains the remains of at least 44 toghers, a word for the wooden trackways that Iron Age and early medieval communities laid across bogland to make it passable. Where most boggy landscapes might yield one or two such structures, Cooleeny produced dozens, preserved in the waterlogged, oxygen-poor conditions that bogs are uniquely suited to provide.

A field survey carried out in 1999 catalogued the full extent of these trackways and revealed considerable variety in how they were built. Most were constructed from a combination of brushwood and roundwood, the latter being small, roughly cylindrical timber sections, but six relied on roundwood alone and eight on brushwood alone. One unusual example incorporated gravel alongside brushwood, a less common technique in Irish bog road construction. Where wood species could be identified across seventeen of the toghers, the range was striking: alder, ash, birch, blackthorn, hazel, mountain ash, and willow all appear, suggesting that builders were working opportunistically with whatever timber was available nearby rather than selecting a single preferred material. Two of the toghers have been radiocarbon dated, both returning Iron Age results. The calibrated date ranges, 388 to 207 BC and 372 to 192 BC, place their construction somewhere in the last few centuries before the common era, a period when Irish communities were moving cattle, goods, and people across landscapes that would otherwise have been impassable for much of the year.