| Mynydd y Grug | |
|---|---|
 | |
| Highest point | |
| Elevation | 375 m (1,230 ft) |
| Prominence | 104 m (341 ft)  |
| Coordinates | 51°36′33″N 3°11′25″W / 51.6091°N 3.1903°W |
| Naming | |
| English translation | hill of the mound/barrow |
| Language of name | Welsh |
| Geography | |
| Location | Caerphilly, Wales |
| OS grid | ST 176910 |
| Topo map | OS Landranger 171 / Explorer 166 |
Mynydd y Grug is a hill lying just west of the village of Cwmfelinfach and about 4 km to the northeast of Caerphilly in Caerphilly county borough in South Wales. Its summit was formerly at a height of around 358 m, but since the top has been covered by a large spoil heap and landscaped its height has now increased to 375 m, though some authorities take other values for the summit height.[1] A number of ancient cairns are found along its edge overlooking the Sirhowy Valley, the slopes up from which are largely wooded.