The Senedd dipped into darkest last night as part of WWF's Earth Hour campaign.
Caerphilly Castle, Cardiff City Hall and the Senedd were among the landmarks around the country to take part in a black out last night as part of WWF's Earth Hour.
The WWF, who are organising Earth Hour, say it's "a fantastic reminder" to protect the planet.
We estimate around half a million adults in Wales took part last year - and today's poll shows that most people share our hope of our country playing its part in a brighter future.
This year's Earth Hour is a special one for Wales as we hold a National Conversation of the future of our nation and prepare for a new Future Generations law - the first of its kind in the UK.
– Anne Meikle, WWF Cymru
If everyone in the world lived as we do in Wales, we'd need more than two planets to support us. But we now have a great opportunity to change and become a sustainable 'one planet nation'.
Iconic landmarks across Wales will turn off their lights this evening for Earth Hour, dubbed the "world's biggest celebration of the planet."
The WWF estimates around half a million people in Wales took part in last year's event.