The B143 is a winding road in south County Fermanagh.
The road starts on the A34 just east of Newtownbutler and heads northeastwards along Magheraveely Road into the village of that name, where it reaches a T-junction and TOTSOs right. It now loses its central line as it leaves town and winds to the east. After going over the Killylacky River the road wheels left onto Lacky Road then turns left at an unsigned TOTSO onto Drumard Road. The road ends at the border close to the small Summerhill Lough, which lies 2.5 km northwest of Clones in County Monaghan. The L2101 continues ahead to Lacky Bridge.
The full length of the B143 in 1946
The B143 was originally unclassified but gained its number in the late 1920s. It seems, however, that the road did not originally TOTSO at the eastern end but instead continued ahead to reach the border (although the present eastern route seems to have been a later spur).
The route then continued ahead towards Clones then turned left onto Lacky Road. This crossed the border another three times (it is assumed the isolated section in County Fermanagh was a detached part of the B143) before regaining its number at Lacky Bridge. It headed north to the B36 at Dernawilt crossroads, 6 km west of Rosslea. This section was downgraded on 11 February 2013 and is now the C707; the reclassification had been opposed by Fermanagh District Council.