It is more than a century since two brothers, armed only with candles, ropes, and a revolver, traced a five-mile underground stretch of the river Llynfell and discovered the caves of Dan-yr-Ogof.
Now, this natural network of wonders forms the largest showcaves in the whole of the UK.
Trevor Fishlock explores underground, and in the hills and valleys around Hirwaun he discovers the story of the iron king who immortalised his workers in a series of specially-commissioned portraits.
Determined to keep alive the memory of aircrew from two world wars, volunteers have renovated the control tower of an airfield.
Trevor Fishlock visited Carew Cheriton, near Pembroke, 15 years ago when the project was in its infancy - and now he returns to see the remarkable result.
One of the project leaders, Deric Brock, says the museum is a tribute to the community’s togetherness - and has become a key educational tool for schools.
Heading into the archive, Trevor walks the River Cleddau to hear the story of Pembrokeshire’s worst mining disaster and the tale of the female aristocrat whose saucy memoir made gentlemen blush.
Trevor Fishlock heads to the Gwili Railway in Carmarthen where for the past 40 years volunteers have been renovating part of a west Wales railway line.
Local historian Jeremy John tells Trevor the story of the Victorian railway and how it revolutionised life in rural Wales.
And he reveals Gwili’s latest project - the renovation of the last steam train ever made in Wales.
Trevor also delves into the archive on a walk through the heart of Snowdonia, where he hears stories of the slate industry and samples a marvellous marmalade pudding.
This week Adrian Masters was joined by Labour's Jenny Rathbone AM, Darren Millar AM for the Conservatives and Colegau Cymru chief executive Iestyn Davies to discuss Brexit and the prospect of expanding the Assembly. Plus Owain Phillips was in Brussels with the First Minister as he met with the EU's chief negotiator Michel Barnier.
Summer Journeys: Ruth Wignall travels to Wales’ smallest city St Davids, in west Wales, and takes a boat trip to Ramsey Island where she learns about the turbulent waters and wildlife. Andrew Price goes off the beaten track in the Cambrian Mountains and discovers a bothy - a stone cottage - which has an open door policy for weary travellers. And Rob Shelley is following in the footsteps of ancient slate quarrymen in the spectacular Snowdonia countryside.
Sharp End was only off air for three weeks and suddenly we have four leadership contests in the Assembly and another UK Government crisis. Joining Owain Phillips to discuss Brexit, leadership and the fun and games awaiting Assembly Members over the summer were Vikki Howells AM for Labour, Dr Dai Lloyd AM for Plaid Cymru and Nick Ramsay AM from the Welsh Conservatives.
We also heard from the latest Labour member to join the First Minister race - Huw Irranca-Davies.
With children as young as 12 dealing drugs on our streets, Wales This Week investigates the phenomenon of County Lines.
We meet the people fighting back against big city gangs, and find out why Wales is a target.
Children's Minister Huw Irranca-Davies is the latest contender to replace Carwyn Jones as First Minister. Mr Davies, who stood down as an MP to become an AM in 2016, says he hasn't approached anyone for backing yet, but hopes his ideas will bring him support. He's been speaking to our Political Reporter Owain Phillips.