A photo gallery on some of the key venues of Tokyo 2020.
With 500 days to go until the Tokyo 2020 opening ceremony, construction is at fever pitch to build the 43 sites that will be located in two main zones.
The "Tokyo Bay Zone", dominated by the city's Rainbow Bridge and in the middle of Tokyo's busy port area, will see several brand-new facilities constructed with views out to the ocean.
The more central "Heritage Zone" will see several sites used at the 1964 Tokyo Olympics reused, refitted or rebuilt.
Here is a look at some of the key venues.
Used for the opening and closing ceremonies, as well as the athletics and some football matches, the Olympic Stadium in the centre of Tokyo is being built on the site of the 1964 stadium.
It has not been completely smooth sailing, as the original design, by Iraqi-British architect Zaha Hadid, was jettisoned in July 2015 amid public outrage over its $2 billion price tag, which would have made it the world's most expensive stadium.
A slimmed-down version was commissioned at half the price but there was a knock-on effect on the 2019 Rugby World Cup, as the final was due to be played there. That match, on November 2, will now be played in Yokohama, south of Tokyo.
The photo shows an aerial view of Japan's National Stadium under construction.
For the Aquatics Centre under construction in the Bay Zone, workers have built a huge roof supported by four pillars 20 metres (65 feet) high.
Rubber cushions are visible between the roof and pillars to absorb seismic shocks in the earthquake-prone capital.
There are also oil damper shock absorbers but the company manufacturing these has been at the centre of a data falsification scandal.
"They will be checked and any replacements will be carried out at the cost of the company," said Daishu Tone, a site director.
The stadium, used for swimming, diving and artistic swimming, plus the Paralympic swimming, will seat 15,000 -- reduced to 5,000 after the Games, when it will host aquatics competitions and be open to the public.
In the image Japanese swimmer Kosuke Hagino (2nd L), Canadian swimmer Kylie Masse (3rd L) posed with Tokyo 2020 Olympic Games mascot Miraitowa (L) and Paralympic mascot Someity.
On a lush artificial island in the shadow of the huge Tokyo Gate Bridge, 300 construction workers are building the Sea Forest Waterway, a two-kilometre-long basin protected from the sea by a dam, where rowers will glide along eight competition lanes.
"Construction is 77-percent complete and should be finished in May" at the venue which will also host canoe sprint, said Yojiro Muraoka, a Tokyo government official in charge of Olympic sites, at a recent media tour.
The arena will seat 24,000 during the Games, reduced to 2,000 afterwards, when it will host 30 competitions per year as well as canoeing and rowing classes.
The photo shows the under construction Sea Forest Waterway.
The brand-new Ariake Arena will host Olympic volleyball and Paralympic basketball, with seating for 15,000. Solar panels on its curved roof were specially placed to avoid beaming sunlight onto nearby residential tower blocks.
Like the Aquatic Centre, it will have solar panels, heat sensors and geothermal pumps to reduce CO2 emissions at the venue, which will play host to concerts and sporting events after 2020.
The photo shows a view of the under construction Ariake Arena.
This martial arts mecca was first built for judo in 1964 and boasts a curved roof that is supposed to resemble Mount Fuji. This time, it will host karate and judo.
In addition to martial arts, it is also a key concert venue and played host to the Beatles in 1966 when they made their first appearance in Japan.
The Olympic Village is being built on reclaimed land on a huge rectangular site looking out over the water. It will have 21 towers stretching between 14 and 18 floors with a total capacity of 18,000 beds during the Olympics and 8,000 for the Paralympics.
After the games, the lodgings will be available to buy or rent.
The photo shows a general view of the under construction Olympic Village.
Kasai canoe slalom
The first artificial canoe slalom course in Japan, the vast concrete basins slope at a two-degree gradient. "Four pumps will be installed and blocks placed on the course to create a raging current," said Muraoka, showing plastic structures the size of a shower cubicle.
Post-Games, the site will be used for a wide range of watersports and leisure activities.
Photo shows the under construction Kasai Canoe Slalom Centre.
Japanese authorities have dubbed Tokyo 2020 the "Reconstruction Olympics" and they are determined to show that areas in eastern Fukushima have been revitalised since the crippling 2011 earthquake, tsunami and nuclear meltdown.
The Fukushima baseball arena will be used for softball and baseball, one of Japan's most popular sports.