The sharp hairpin bend known as 'The Vee' which gives its name to this section of the R668. The road was constructed as a famine relief project in 1846-7.
The R668 runs from Cahir in County Tipperary south to Lismore in County Waterford by way of Ballylooby, Clogheen, and the Vee Gap through the Knockmealdown Mountains.
In the 18th century the section between Cahir and Clogheen formed part of the main road from Cashel to Cork. It was superseded in this role in the early 19th century by the construction of the road that would later become the N8 and is today the R639 road between Cahir and Mitchelstown.
The section from Clogheen to Lismore offers some spectacular views as it climbs to 350 m to pass through the Vee Gap (Irish: Bóthar na gCorr – "the edge road") between Sugarloaf Hill (663 m) and Knockshanahullion (652 m) in the Knockmealdowns.
The R668 terminates at a junction with the N72 at Ballyrafter, on the north side of the River Blackwater facing Lismore.