It’s well-known that there are miles of layers between the ground we walk on and the solid core of the Earth, some 4000 miles away. But how close can you get to that core? There are places on Earth which naturally go down to unbelievable depths, and then there are man-made structures that try to reproduce that. This list could easily consist of nothing but ocean trenches, but for a bit of variety we’ve included some other deep places, some of which are accessible…but most are not. Find out more in our Top 10 Deepest Places on Earth.
10. Woodingdean Well
We’ll start with a man-made feat, and a remarkable one at that. Going down to 850 feet below sea level, the Woodingdean Well is the world’s deepest hand-dug well and was started in 1858. It took 4 years to complete and in total was 1285 feet, although the initial plan was to dig just 400. It was all done by groups of men on rickety ladders, sweating in the intense heat of the hole and at least one man lost his life during the project. Even more remarkably, it was dug largely by paupers from the local workhouse who, presumably, were in no position to complain about the extremely unsafe conditions. The hole is still there, deep into the earth, but has been covered over at the surface level.
9. Tagebau Hambach
At 961 feet below sea level, the Tagebau Hambach mine is an open lignite mine in Elsdorf, Germany and it is the deepest open mine in the world. The whole mine is 1213 feet deep and contains the biggest excavator in the world, which removes around 24,000 tonnes of lignite every day – around a stadium’s worth. It even has its own tourist attraction – Sophienhöhe, an artificial wooden hill from which visitors can see the mine. It’s also a record holder in its own right, being the biggest artificial hill in the world – at 990 feet above sea level, it’s as high as the mine is deep. Both are worth visiting!
8. El Zacatón
And now for something that’s not artificial – the world’s deepest sinkhole. Sinkholes are a curious natural phenomenon, as they just appear in the Earth with no warning and when this happens in populated areas, the devastation can be terrible. However, this is no new sinkhole – Zacatón in Mexico has been around since the Pleistocene, and is a beautiful natural feature, filled with water. It goes down to 1112 feet below sea level, which was measured by an automated robot. Humans have also tried to reach the bottom, with a pair of divers in 1994 getting down as far as 925 feet. However, one of them – Sheck Exley – sadly died from high pressure nervous syndrome at around 900 feet, showing that depths like this can be dangerous, even for highly experienced cave divers (Exley was an expert in the subject and had written books about it). Since then, no other people have attempted to reach the bottom. Beautiful but dangerous.
7. Lake Baikal
Another natural wonder, Lake Baikal in Russia is the deepest lake in the world, reaching down to 5,387 feet. There has been much exploration of the lake, with the Russian Academy of Sciences sending small submersible craft down there in 2008 and they reached a depth of 5,180 feet, failing to break the world record for deepest freshwater dive (the record was also set in Baikal, by Anatoly Sagalevich in 1990 and he reached 5,371 feet). But the scientists are not the only ones with an interest in Baikal – it’s also much desired by the leisure industry, as the clear waters – known as the “Pearl of Siberia” – bring tourists flocking to its shores. New hotels and an adventure trail are being planned for the lakeside but thankfully other plans in the region – like installing an oil pipe under the lake – have come to nothing. So it looks like Baikal will be preserved for the future, and one day someone might even reach the bottom of it…
6. Krubera Voronya Cave
Now, here’s one that’s not for anyone who’s a bit claustrophobic. Voronya cave in Georgia is the deepest cave in the world, reaching down 7,208 feet. The cave actually has two names – Krubera was given to it in the 1960s, after the Russian geographer Alexander Kruber but the explorers who came later called it “Voronya Cave” which means “Cave of Crows” – after, of course, the crows that gathered there. Since 2000, expeditions down the cave have become a yearly occurrence, with teams from the Ukraine, Britain, France and Spain attempting to establish just how deep it is. Expeditions during the 80s regularly pushed the cave depth up by hundreds of meters – it might be that Voronya is much deeper than we even suspect. It’s certainly the only cave on Earth deeper than 2000 metres (6,561 feet) and mapping it is a daunting and very long-term task!
5. Kidd Mine
The deepest mine on Earth is Mponeng Mine in South Africa, at a depth of 13,123 feet. However, the mine that goes deepest below sea level is Kidd Mine in Ontario, Canada which reaches 8,967 feet below sea level. The total depth is around 10,000 feet and as it’s so far north, it is closer to the center of the Earth than any other mine. It opened in 1964, as an open-pit mine and has gradually expanded underground. It is now the biggest copper mine in the world, employing 2,200 workers and producing millions of tonnes of ore every year. It is due to close in 2017 after receiving extra funding in 2008 to carry on work until then.
4. Litke Deep
As mentioned earlier, the deepest places on Earth all tend to be under the ocean. So here’s the deepest Arctic trench – the Litke Deep in the Eurasian Basin. At 350 km north of the “arctic wilderness” of Svalbard, it’s at one of the extremes of the Earth, so as well as being very deep (17,881 feet) it’s also very cold. It’s the 20th deepest ocean trench in the world and probably one of the most inhospitable places in the world. It was named after the ice-breaking ship that discovered it in 1955 – the Fyodor Litke. The icebreaker had been in service since 1909 and had been heavily used in the Soviet era for Arctic exploration. It also served during the Second World War and was eventually scrapped in 1960.
3. Milwaukee Deep
There are many deep trenches in the Atlantic Ocean – the Romanche Trench at 25,459 feet and the South Sandwich trench at 27,650 are just two of them. But the deepest of them all is the Puerto Rico Trench, and specifically the Milwaukee Deep, which reaches 28,680 feet below sea level. It’s found 76 miles north of Puerto Rico and was named after the USS Milwaukee, which discovered the deep on February 14th 1939 and recorded the reading of 28,860 feet. 13 years later, the wildlife vessel Theodore N. Gill also measured the deep and recorded a depth of 28,560 feet.
The Puerto Rico Trench itself is located along the border that marks where the Caribbean Sea ended and the Atlantic Ocean starts. It’s near a fault zone, which raises geologists as they believe it might cause an earthquake very soon, which in turn would generate a tsunami. It’s not happened yet, which is why geologists feel it’s overdue for a major event. A very deep and very dangerous trench.
2. Mariana Trench
The top five deepest trenches are all in the Pacific Ocean – the Tonga Trench, the Philippine Trench, the Kuril- Kamchatka Trench and the Kermadec Trench are all over 30,000 feet deep but the deepest of them all is the Mariana Trench, at an amazing 35,994 feet deep. Being the deepest in the world, it has been the subject of much exploration and at one point there was an intense competition between entrepreneur Richard Branson and film director James Cameron as to who could reach the bottom first. Cameron won, reaching the bottom in March 2012. He descended in his “torpedo sub”in 2 hours 36 minutes before spending a few hours taking samples from the trench floor. He then noticed oil leaking from his 43-inch sub and so decided to ascend before he was stranded down there. There are several unusual lifeforms at the bottom of the trench, including foot-long amphipods and sea cucumbers that camouflage themselves against the sandy bottom. There is almost certainly more to be discovered at the bottom of the trench and, given the interest in what lies down there, there’s bound to be more explorations soon.
1. Kola Superdeep Borehole
The deepest place on Earth is somewhere that’s never been accessed by human beings, but it is man-made. It’s the Kola Superdeep Borehole and it’s the deepest hole ever drilled, at 40,230 feet underground. When the project started in 1970, the aim was 49,000 feet but the temperatures were higher than anyone expected -356F – and if they’d got to 49,000 feet it would have gone up to 572F, which would be a difficult temperature for the drill to work out, even if it didn’t just melt. So drilling stopped in 1992 and reached a third of a way through the continental crust. The current record holder for longest borehole is currently Odoptu OP-11 well at 40,502 ft, but the Kola Borehole remains the deepest hole below the surface ever drilled.