I recently visited Iwaki, Fukushima province to visit Spa Resort Hawaiians. Partially because it sounded interesting, and partially to buck the trend of overseas tourists avoiding Fukushima province.

I noticed publicly visible radiation counters while I was there. The one below, in a photo taken by a taxi driver who noticed me trying to take a photo by myself, was near Iwaki train station, but there was also one near the Iwaki City Coal and Fossil Museum.

Photo of me next to a radiation counter, wearing an "I [akabeko] Fukushima" tshirt. Reading is 0.164 microsieverts per hour

Although I assume the counters were designed to reassure locals and tourists that radiation levels are reasonably low, for me it served as a bit of a "been there, done that, got photo proving it" thing, even if it turns out 0.164 microsieverts per hour is less than the global average of background radiation. It got me wondering which places on earth that I can visit have the most radiation.


  • Both man-made and natural radation are of interest: I'm interested in both human history and in geology.
  • Reasonably accessible: something accessible to ordinary tourists, not only journalists or nuclear scientists or local residents.
  • Well documented: an area having information about its radiation (eg how a nuclear accident occurred, or the history of nuclear weapon testing at the place) would be preferable.
  • Radiation levels available: ideally some public structure like the one I was photographed with, but otherwise a place where radiation measurement devices are not prohibited.
  • Tourists welcome: if tourists aren't welcomed in an area by locals for legitimate reasons, then I'd be understanding of that.
  • On earth. Can't be the moon or Mars!

If there's a place on earth that has the least amount of radiation, and it is open to tourists, then I'd be interested in visiting that as well.

  • 1
    What about radiation from the sun? Eg Bolivia, high altitude, low atmoshphere = higher radiation, or NZ where there's higher chance of skin cancer due to Ozone holes?
    – Mark Mayo
    Sep 30, 2012 at 6:08

3 Answers 3


The place with the highest natural background radiation on Earth is Ramsar, Iran, due to the presence of radioactive hot springs in the area:

In the high-background radiation districts of Ramsar, the average dose of radiation received by a person for one year is about 10 mSv, and can reach levels in excess of 260 mSv. [Wikipedia]

The place with the historically highest natural radioactivity is Oklo, Gabon, where there are extensive uranium deposits that formed natural nuclear fission reactors 1.7 billion years ago:

Oklo is the only known location for this in the world and consists of 16 sites at which self-sustaining nuclear fission reactions took place approximately 1.7 billion years ago, and ran for a few hundred thousand years, averaging 100 kW of power output during that time. [Wikipedia]

While a chain reaction is in place, radiation levels rise to extreme levels, much higher than any usual background radiation. I have no information about the specific levels at the Oklo sites, but you can read here about what happens when a nuclear core goes critical.

  • Wikipedia mentions the former as a popular tourist destination, which is a positive.
    – Golden Cuy
    Oct 7, 2012 at 20:35
  • 1
    These were high grade (higher than normal U235 content) ore deposits moderated by groundwater. Since they were underground, direct radiation at the surface was likely fairly low (rock shields neutrons and gamma rays). However, radioactive fission products and other nuclear products may have made it to the surface. These ancient reactors were discovered by nuclear monitors puzzled as to why the U235 content was lower than normal in the mines' ore -- it was burned up.
    – Phil Perry
    Jun 4, 2014 at 18:08

So it depends a lot on how you define it.

If we go the Wikipedia route, it'll be Lake Karachay in Western Russia. The Soviet Union used Karachay as a dumping site for radioactive waste from Mayak, the nearby nuclear waste storage and reprocessing facility, located near the town of Ozyorsk (then called Chelyabinsk-40).

Then we have the Irish source, which claims that the most radioactive place on Earth is in Cumbria, England - the problem being that nobody knows for sure how radioactive it is, or what's inside - a fact backed up by Wikipedia.

Finally, and this one's far more interesting, is Shinkolobwe, in the Congo. It's where a large amount of the world's uranium has come from, and certainly at least several thousand tons of uranium has gone from there to the US alone, including the uranium in the atomic bombs dropped on Japan. The mine has long since (allegedly) closed, but again allegedly - people have been sneaking in to get bits of uranium out to sell on the black market. This is covered in great deal in this Scientific American excerpt of Tom Zoellner's book Uranium.

  • 1
    The Cumbria place is interesting, but link is full of bull-shit; anyone who's mildly knowledgeble in the field will tell you.
    – Jacco
    Sep 30, 2012 at 18:25
  • @Jacco - yeah, sensationalistic Irish journalism ;) but it did claim it was the most, so I included it, but also clarified with the Wiki page.
    – Mark Mayo
    Sep 30, 2012 at 18:41
  • Interesting reading on Lake Karachay
    – Jonik
    Sep 30, 2012 at 19:19
  • @MarkMayo, I'm not criticising your answer, just the sensationalist linked article : )
    – Jacco
    Oct 1, 2012 at 6:24
  • @Jacco - I thought as much, but felt worth clarifying for other readers ;) Cheers.
    – Mark Mayo
    Oct 1, 2012 at 6:40

You can book tours (from several operators, easily found on the web) to the Chernobyl power plant, including visits to the abandoned city of Pripyat and the red forest (an area where intense radiation fallout killed most of the vegetation).

I believe that the tour guides will have radiation measurement devices to show that the background radiation is back to normal - but you'll be within a short distance of the concrete "sarcophagus" around the reactor where the accident occurred, and the deeper levels of soil are still heavily contaminated in some areas. Eating any local fruit should of course be avoided - I recently saw an interesting TV show about research in that area on various plants' very different reaction to radiation. IIRC birch trees easily survived while spruce trees proved much less resilent - and some fruit and vegetables (or even parts of them) are much more dangerous than others, e.g. you can eat cherries but must not swallow the pits.

  • 2
    I've heard if you bribe the guides then you can even get into some of the buildings where radiation levels are much higher. Sep 30, 2012 at 13:15
  • 2
    @AnkurBanerjee If you bribe the guides, you can get into much more than buildings. I'd advise against it :)
    – Tim Post
    Sep 30, 2012 at 15:26
  • 4
    Having done the tour myself, I can confirm that you do get geiger counters, and you get to within 400m of the reactor and sarcophagus. Certainly plant matter seemed to be better at absorbing radiation - ground moss in the fairground in Pripyat contained the highest levels that we observed. Saying that, it's no more radioactive than the hundreds of nuclear power plants around the world, and indeed is less radioactive than most of them, having had time for one of the three isotopes to degrade substantially. Still, as a site to visit, it's fascinating! :)
    – Mark Mayo
    Sep 30, 2012 at 17:18
  • @TimPost Is the "much more" the nuclear reactor, or a Ukrainian jail?
    – Golden Cuy
    Mar 16, 2013 at 1:03
  • @AndrewGrimm maybe he meant Ukrainian prostitutes ;) but yes, a jail would be a place you can expect to end up if you try to bribe people.
    – jwenting
    Sep 13, 2013 at 12:54

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