Monmouth, Welsh Trefynwy, town (1981 pop. 7,379), Monmouthshire, SE Wales, at the junction of the Monnow and Wye rivers. The town is a popular tourist and agricultural center with flourishing cattle and produce markets. Industries include food processing and paper manufacture. Fishing is also an activity. Remains of a 12th-century castle (in which Henry V was born), a Norman church, and an old bridge (1272) over the Monnow are there. Monmouth School for boys was founded in 1614. A local museum commemorates Admiral Horatio Nelson's numerous connections with the town.