The B187 was a short link road in north County Londonderry. It was originally unclassified but gained its number in the late 1920s. However, the road was short-lived and is shown as declassified on the 1946 OSNI Road Map. The road has now regained Class II status as part of the B207.
The road started on the A29 to the south of Coleraine and headed southeast along the dead-straight Moneybrannon Road. The road crossed fields as it continued across flat land. After crossing the River Aghadowey the road ended on the B66.