HOELWERMOOD (HOEL-CHWERMWD), a hamlet, in the parish of MERTHYR-TYDVIL, hundred of CAERPHILLY, county of GLAMORGAN, SOUTH WALES, adjoining the town of Merthyr-Tydvil. The population is returned with the parish. In this hamlet is situated the principal part of the extensive and populous market-town of Merthyr-Tydvil. It contains the Dowlais, Penydarren, and other iron-works, and the Plymouth furnaces, and abounds with coal and iron-ore. The Taf Vawr river flows on its western side, on the left bank of which proceeds the road from Cardiff to Merthyr- Tydvil. 'At Twyn y waun, an eminence on the eastern side of the hamlet, fairs are held on the first Monday in July and the first Monday in August, and horse-racea occasionally take place: near this eminence passes the road to the Tredegar iron-works in Brecknockshire. The lower part of the hamlet, on the banks of the Tif, is tolerably well wooded.