The two UNESCO structures in Croatia, Diocletian's Palace in Split and the Walls of Dubrovnik, went "lights out", as did Croatia's most famous symbols, including Pula's Arena amphitheatre, Zagreb's Cathedral, and the old towns of Rijeka, Zadar and Osijek.
Street lights were switched off along the Makarska Riviera, putting 80 km square kilometres of the coast in darkness, said Petra Boic Petrac, Earth Hour project manager.
The campaign is held annually across the globe in support of efforts to prevent climate change. Earth Hour was launched in Sydney, Australia in 2007 when 2.2 million people and over 2,000 businesses turned off their lights to raise their voice against climate change. It has since become a worldwide movement with hundreds of millions of participants in more than 180 countries across the globe. It is the largest global voluntary action in history.