In the spring, it is a popular cherry blossom viewing spot. For the Christmas season, it is transformed into an LED wonderland.

But it is how these lights along the Meguro River in Tokyo are powered that makes the view all the more impressive.

Local restaurants and neighbourhood residents supply old cooking oil, which is used to fuel the more than 420,000 lights along the path.

Each year, organisers salvage around 5,400 litres of old oil to keep the flowers lit.

"We collect used cooking oil and purify it into biodiesel fuels, and then put it on the power generator that lights up the LED lights," said organiser Hajime Narita.

The project, called Illumination For All, is marking its seventh year, tracing back to the 2011 Fukushima nuclear disaster when the country went dark from power shortages.

Now, it has become a display that locals look forward to every year.

"I think it's great that they take waste products and make them into something beautiful," said 27-year-old businessman Makoto Kinoshita.

REUTERS