Monnow

The Monnow is a river in south-eastern Wales, a tributary of the River Wye. It rises on the slopes of the Black Mountains near the England–Wales border and flows generally northeast to Monmouth, where it joins the Wye.

In Welsh, the river is called Afon Mynwy; the English name Monnow developed from this form. The exact etymology is uncertain, but its name reflects the river’s long-standing place in local geography and history.

The Monnow passes through a mix of upland farmland and wooded valleys. Its upper valley is noted for the trio of Norman fortifications known as the Three Castles—Skenfrith, White Castle, and Grosmont—built to guard the river crossing and secure the Monmouthshire landscape. The river’s lower reaches near Monmouth form a picturesque corridor that has long linked settlements and trade.

Historically, the Monnow has served as a boundary and connectivity line in the Welsh Marches. Monmouth, situated at the confluence with the River Wye, developed as a market and administrative centre in part because of this crossing point. The river valley remains a focus of local heritage, tourism, and landscape conservation.

Ecology and recreation along the Monnow reflect typical Welsh river environments. The water supports species such as brown trout and other freshwater fish, while otters and kingfishers are among the bird and mammal visitors. The Monnow island and riverbank habitats are used for walking, fishing, and small-boat activities in appropriate sections and conditions.