Twenty-five years after a reactor at Ukraine's Chernobyl nuclear power plant exploded and melted down, its surroundings are well-explored territory, including the abandoned workers' town of Pripyat, two kilometers (about a mile) from the plant. The guides who take visitors through the area know exactly where to go and, more important, what to avoid.
They keep visitors at a safe distance when taking pictures of the Orange Forest, where heavy fallout still emits severe doses of radiation. They do not take their charges to a parking lot full of helicopters and firefighting vehicles; they were used to extinguish the fire at the reactor and remain contaminated. But it is fine to walk up to the fence a few hundred meters (yards) from the shattered reactor, now enclosed in a concrete tomb called the "sarcophagus."
Associated Press photographer Sergey Ponomarev documented life inside the exclusion zone around the Chernobyl nuclear power plant in April 2006 and June 2011. Last April, as the 25th anniversary of Chernobyl approached, he was on assignment in quake-stricken Japan, and photographed life in the city of Futaba, in the evacuated zone around the crippled Fukushima Dai-ichi nuclear plant.
The people who fled Futaba, the town nearest to the Fukushima plant, need only look to Pripyat, some 8,000 kilometers (5,000 miles) away, for a hint of what it will probably turn into: a ghost town forever looking as though it expects its 7,000-plus people to return any minute.
In Futaba, unlike in Pripyat, you are in uncharted territory. There are no guides. The radioactive hot spots are uncharted, and behind every corner, danger may lurk that will not turn malignant for years, even decades. Radiation cannot be sensed like a hum or a smell. The sun shines and the wind blows, and only the beeping of your Geiger counter tells you something is wrong.
Futaba and its environs are a fresh wound. The Fukushima plant still is unstable. Pripyat, once a town of 50,000, is an aging urban wilderness with trees growing through cracked asphalt. In both places, stray dogs and cats are a reminder that ordinary people used to live there. But there are big differences too.
Pripyat has been a ghost city long enough to be a magnet for thrill-seekers and artists. They include the world-famous, ever-elusive graffiti artist known as Banksy. In one kindergarten, the toys have been rearranged to look as though they are playing with each other. In another, a doll wears a gas mask.
Futaba is virgin territory, at least until the day the tourists start venturing in.