Manly beach glows with intense neon blue lights Monday night.
The amazing natural phenomenon is called bioluminescence. It happens when microscopic marine animals in bright red algae reacts when stimulated by the crashing waves.
Photographer Joel Coleman described the colour as intense. He said it was more beautiful when a wave would come as it light up the whole beach.
It was something unbelievable, really beautiful as there was a particular instance when the entire waves was glowing in neon blue greenish colour, Newport resident Tiffany Harper told The Daily Telegraph.
The phenomenon does not cause the water to be toxic, but just as the same, swimmers are advised to avoid it.
"It does excrete an type of compound that can that can agitate the skin if it gets into high concentrations. The particular species common in south east Australia is called noctiluca. They also cause the red tide phenomena which is common off the Sydney beaches, " Sydney Institute of Marine Sciences' Dr Luke Hedge said.
Hedge added that the microorganisms probably came from an animal called a dinoflagellate which measures 0.5mm and which consumes minute sizes of planktons. The glowing colour suggests that the animal is well-fed.
"Bioluminescence has been correlated with nutrition in noctiluca, so it's possible that this 'glow' around Manly is the result of ocean currents or upwelling that are favourable for noctiluca growth and transport onto Sydney's beaches," Hedge added.
The phenomenon also suggests that spring is already coming, University of NSW School of Biological, Earth and Environmental Sciences Professor Iain Suthers said.
Suthers also said that normally there is a good chance that there will be more glowing in the nights to comes.
Such natural phenomena make good for a unique travel experience.
Australia's Lake Hillier, with a thick bubble-gum-pink colour located on the edge of Recherché Archipelago's largest island in the country, still puzzles travellers and experts alike. Some scientists speculate that the pink colour might be a reaction of sea salt and sodium bicarbonate or cause by red halophilic bacteria in the salt crusts.
The video below, from List 25, compiles the top 25 natural phenomena around the world.