Well-known landmarks across Scotland including the Forth Bridge and the Kelpies are being plunged into darkness to mark this year’s Earth Hour.
A number of buildings and structures are turning off their lights from 8.30pm to 9.30pm on Saturday night as part of a call for action to save the planet.
The switch-off is part of an annual international event organised by the conservation charity WWF to highlight the impact humans are having on the planet through climate change, pollution, plastic and food production.
Other Scottish landmarks joining the campaign include Edinburgh Castle, Eilean Donan Castle, the Borders’ abbeys, St Magnus Cathedral in Orkney, Clickimin Broch in Shetland, the Titan Crane in Glasgow, the RRS Discovery in Dundee and the Isle of Lewis war memorial.
Elsewhere in the world, the Sydney Harbour Bridge, Times Square in New York and the Eiffel Tower in Paris are among the sites where lights are being switched off.
More than 7,000 cities and millions of people are expected to take part this year to send a message to leaders that protecting the Earth should be top of their agenda, WWF said.
This year, as well as switching off for an hour, the environmental charity is asking people to make a pledge to change one thing in their lives that will help protect the planet.
Options include restoring nature in your neighbourhood, planning a holiday closer to home, washing clothes at 30 degrees or changing the way you eat.
WWF Scotland director Lang Banks said: “Our world is under threat like never before.
“From our forests to our oceans, wildlife and marine populations are being devastated by the impacts of humans and changes to the climate.
“We know many people here in Scotland and globally want to do something but are not sure where to start.
“By coming together with millions of people around the world for Earth Hour, we create a strong, united voice that changes things for the better.”
He added: “We’re the first generation that knows the extent of the damage we’re doing to our planet and we could be the last that can do anything about it.
“That’s why I’m asking everyone to raise their voice for the planet by making a pledge and taking part on Saturday.”