The day dawned misty but the weather forecast was ‘clear by lunchtime’ as we left Wenvoe. We started in Fernlea near Risca, climbing some steep streets and walking past allotments. We found the route to the footpath was blocked so headed back the way we had come to take a detour through housing (and more very steep roads) and 2 children’s play areas. Skirting a new development we headed into countryside and northeast towards Pant Yr Eos reservoir.

On reaching a minor road we turned northwest in the general direction of Twmbarlwm. The flattened bodies of 8 frogs were spotted along a ½ mile stretch of the road no doubt caught by local traffic during their migration to breeding sites. As we climbed visibility decreased until we were in a thick fog. Now we were totally reliant on maps and GPS as we could see no more than about 50 yards. Spotting stiles across a field was impossible but a good track was clear once we arrived at Twmbarlwm Common. Twmbarlwm was invisible so we walked slightly further than necessary along this track now heading north. We turned west along another track, suddenly a dark shadow loomed over us in the fog. We had been walking uphill all morning and now we followed an excellent path which spiralled up Twmbarlwm.

Twmbarlwm is an Iron Age hill fort, which lies at the heart of the territory of the Silurian Celts. With commanding views over the Bristol Channel it must have played a large role in the 25 years of war which the Silureans fought against the Roman invaders. The impressive earthworks were constructed around 500BC, long before Rome invaded. The raised circular mound is a ‘motte’ built during the 12th or 13th century by the next invaders – the Normans. It must have supported a timber built castle, and the rest of the wider enclosure would have been the ‘bailey’ to protect the horses and live stock of the soldiers.

The magnificent views (on a good day you can even see the two Severn bridges) were totally hidden by the fog, so we admired the stonework in the footpath and walked to the highest point. Descending we headed northwest and ate our lunch when we reached the road where the ‘Raven Walk’ (a 12 mile 3000+ft circular walk) crossed our route. As we sat, a raven cawed high up in a tree – he was barely visible but stayed until we resumed our walk.

Now we shared a short but steep section of path with cyclists. Through Coed Medart we took a good track and as we continued to descend suddenly came out of the fog and could see the valley below us. The cycle track crossed our path and some daredevil cyclists came careering down the hill and disappeared out of sight down the opposite slope – bit too exciting for me. One cyclist had hit a rock and his front tyre had a deep ‘v’ stamped into it – he had his bike upside down and was attempting a repair.

Our return journey was a pleasant meander down good tracks in a southerly direction until we reached the Brecon and Monmouth canal.

This stretch of the canal is the ‘Crumlin Arm’ and runs for 16km from Cwmcarn to Newport. Opened in 1796 from Crumlin, it was worked until the 1940s. Over Greenmeadow bridge lie the shattered bodies of a number of miners who died in the Blackvein colliery disaster of 1st December 1860. An explosion of firedamp (an explosive coal gas found in mines) and the effects of afterdamp(a suffocating gas left after an explosion of firedamp) killed 142 men and boys working the rich vein of steam coal known as the Blackvein. Many of the dead, however were taken by their families to be buried in their home towns – in England. Locals refused to work the Blackvein as the pit had a reputation for high levels of firedamp, the lethal price of the prized steam coal.

The elegant curved bridges crossing the Crumlin Arm were built to withstand the gentle clip clop of horses’ hooves rather than the rumble and thunder of heavy motor vehicles. Afraid that the bridges would collapse, the Great Western Railway Company which took control of the canal in 1880, installed large diamond shaped warning signs to stop overweight vehicles in their tracks. Darran Bridge and others on this section of the Crumlin Arm now have extra protection having been awarded the status of ‘listed building’.

Cwmcarn houses a visitor centre built on reclaimed colliery land in the 1970s. It is known for Forest drive, bicycle trails and panoramic views and has become a tourist attraction.

An easy walk along the canal covered the final stretch, allowing our tired muscles to recover a little. Arriving back at the cars we had covered 8miles and 1500ft. Map 152