sentences:  The summit is also known as Twyn Ffynhonnau Goerion.Some to the southeast lies a major subsidiary top of the hill, Mynydd Varteg Fawr (549m) at the southeastern end of whose broad ridge is a trig point at 544m.A few hundred metres to the southeast of this summit is a memorial known as the "Dog Stone" which commemorates "Carlo the Red Setter", a dog shot accidentally by his master while hunting on the 12 August 1864.