[mon-uh-guh
n, -han] 
| a county in the NE Republic of Ireland. 51,174; 498 sq. mi. (1290 sq. km). County seat: Monaghan. |
Monaghan
one of the three counties of Ireland forming part of the historic province of Ulster, projecting northward into Northern Ireland. Most of the county's northern boundary winds through cultivated lowlands except on Slieve Beagh, a desolate upland rising to 1,221 feet (372 metres). For many miles the boundary with Northern Ireland runs along the River Blackwater
Learn more about Monaghan with a free trial on Britannica.com.