Ben Peach in the context of The Geological Structure of the North-West Highlands of Scotland

Kampecaris is an extinct genus comprising the Kampecarida, an enigmatic group of millipede-like arthropods, from the Silurian and early Devonian periods of Scotland and England. They are among the oldest known land-dwelling animals. They were small (20–30 millimetres (0.79–1.18 in) long), short-bodied animals with three recognizable sections: an oval head divided along the midline, ten limb-bearing segments forming a cylindrical trunk that tapered slightly towards the front, and a characteristic swollen tail formed by a modified segment that tapers at its rear into an "anal segment". The cuticle forming their exoskeletons was thick, heavily calcified, and composed of two layers.

The genus was named by David Page in 1856 for a "small phyllopod, or the larval stage of some larger crustacean" from Silurian deposits of Angus, Scotland (formerly Forfarshire), but it was not until 1882 that B. N. Peach recognized the affinities of this animal to millipedes and named the species K. forfarensis. Peach named another Silurian species, K. obanensis, from Old Red Sandstone deposits from the Scottish island of Kerrera in 1899; John Almond questioned the affinity of this species to Kampecaris in 1985, for several reasons including the presence of 14 segments behind the head. In 1951, B. B. Clarke described a Devonian species, K. dinmorensis, from Dinmore Hill, Herefordshire, England. Another Devonian species, K. tuberculata, was subsequently recognized as being closer to flat-backed millipedes in the group Archipolypoda, and renamed to Palaeodesmus.

Knockan Crag (Scottish Gaelic: Creag a' Chnocain, "crag of the small hill") lies within the North West Highlands Geopark in the Assynt region of Scotland 21 kilometres (13 mi) north of Ullapool. During the nineteenth century Knockan Crag became the subject of much debate when geologists noted that the Moine schists at the top of the crag appeared to be older than the Cambrian and Ordovician rocks such as Durness limestone lower down. Disagreements over the processes that could have caused this to occur were referred to at the time as the "Highlands Controversy". The argument was primarily between Roderick Murchison and Archibald Geikie on the one hand and James Nicol and Charles Lapworth on the other. Murchison and Geikie believed the sequence was wrong and that the Moine schists must be the younger rocks. The controversy was finally resolved by the work of Ben Peach and John Horne whose 1907 paper on the subject remains a classic text. Peach and Horne demonstrated that the situation resulted from the action of a thrust fault - this being the first to be discovered anywhere in the world. The older rocks had been moved some 70 kilometres to the west over the top of the younger rocks due to tectonic action.

The crag is designated as a national nature reserve (NNR) due to its geological features, and is owned and managed by NatureScot. There is a car park and interpretation centre that explains the geology of the area and gives background to the Highlands Controversy, along with three waymarked trails that take visitors to points of interest across the site. The site also hosts artworks such as 'The Globe' by Joe Smith and 'Pipeworm’ by Susheila Jamieson that were commissioned to highlight the inspiration that the landscape has had on artists and poets.