Parc Cefn Onn
Parc Cefn Onn.
The park was closed as they are installing ramps and a diversion skirts the eastern edge of the park. In February, Camellias were in full flower and the red trunks of Acers stood out.
Entering open countryside we climbed onto the ridge and walked parallel to the coast. Views extended west of Wenvoe to Penarth, the whole of Cardiff and beyond. We passed an old gnarled, hollowed out tree and a boundary wall dripping with moss.
Climbing through the woodland at Coed Coesau, most of the trees had lots of exposed roots. Curiously large metal hawser-like ropes looped from tree to tree at the edge of the path.
At lunch time we climbed to the top of a crag enjoying views of Caerphilly Mountain to the north and the coast to the south.
Our return journey followed the Rhymney Valley Ridgeway footpath. In one section a steep descent was negotiated via a long stretch of steps.
The path passes over Caerphilly railway tunnel which was built by Rhymney Valley railway to avoid paying to use tracks owned by Taff Vale railway. The tunnel is over 1 mile in length. Construction was started from 5 shafts sunk from the surface of the mountain. These are now ventilation shafts but originally provided access and pumped out vast quantities of water which were a continual problem for the tunnellers. They were also the scene of fatal accidents; a man was crushed by machinery in No. 4 shaft and seven men died in No. 3 shaft when the skip, in which they were descending, fell down the full length of the shaft. Hidden deep in a manmade valley lies what was formerly Cefn Onn Halt, near the entrance to the tunnel.
A large bank of daffodils at the entrance to the park glowed on an overcast but warm day, with a cool breeze at lunchtime. The walk was 7.4 miles 750ft ascent. Map 151.
1975. We started by walking along the Ogilvie lake. There are a few sculptures to the side of the path and numerous pieces of outdoor gym equipment (the Ogilvie Olympics obstacle course) together with old mine wheels. We climbed in an easterly direction away from the park and took a slight diversion to look at a waterfall and moments later we were at the top of it. Continuing our climb we spotted a farm with birds in its yard – geese, ducks and hens. In the distance we could see cows and sheep chasing after a tractor delivering food. 
son of Martius’. The original stone probably dates back to the early 7thC but may be much older marking the grave of a Roman soldier from their campaign in the area 47 – 113 AD. There is also the Capel Brithdir Monument now housed in St Gwladys church, Bargoed and a Celtic cross.