<p>Probably a bit over 4 km, in this South African mine: <a href="https://en.wikipedia.org/wiki/Mponeng_Gold_Mine" rel="noreferrer">https://en.wikipedia.org/wiki/Mponeng_Gold_Mine</a>  But as the link mentions, the mine operators go to considerable lengths to reduce the mine temperature to endurable levels from the  66°C/151°F of the surrounding rock.</p>

<p>Note: This answer is for the original question, where the OP asked for the deepest depth below the surface.  It's since been changed to ask for depth below sea level.</p>

<p><a href="https://i.sstatic.net/VwkFT.jpg" rel="noreferrer"><img src="https://i.sstatic.net/VwkFT.jpg" alt="enter image description here"></a></p>

<p><a href="http://cracked.tumblr.com/post/162183647834/the-mponeng-gold-mine-in-south-africa-is-the" rel="noreferrer">http://cracked.tumblr.com/post/162183647834/the-mponeng-gold-mine-in-south-africa-is-the</a></p>

CC BY-SA 4.0
2018-05-16T08:38:39.520Z
How far below the surface is the natural water table at the mine? Because once the mine is eventually abandoned, when the recoverable gold has been mined, the pumps will be turned off & the mine will flood, which will reduce the depth that anyone could have access to while breathing air.
Fred
CC BY-SA 4.0
2018-05-16T16:46:28.427Z
@Fred: But if it's abandoned, nobody will be down there anyway.
Lightness Races in Orbit
CC BY-SA 4.0
2018-05-16T17:38:02.897Z
@LightnessRacesinOrbit: Not necessarily. It may be abandoned by large mining companies for mining purposes but it could be re-purposed. Smaill scale illegal miners could attempt scavenging operations or it could be used for scientific purposes such as the former [Homestake Mine ](https://en.wikipedia.org/wiki/Homestake_experiment) which is housing an experiment to detect neutrinos produced by the Sun.
Fred
CC BY-SA 4.0
2018-05-16T17:39:01.870Z
@Fred: Not if it's flooded ;)
Lightness Races in Orbit
CC BY-SA 4.0
2018-05-16T17:41:01.780Z
The usable depth depends on the water table & how much of the mine is flooded.
Fred
CC BY-SA 4.0
2022-12-18T23:21:17.630Z
There are so many mines along the 56 km long Witwatersrand gold reef in South Africa that the water levels in many abandoned mines is kept down by pumping in adjacent working mines. In the 1990's I went on a mine tour of one that that was abandoned in the 70s. We went to just short of the bottom of the first 1km deep shaft, where the water level was. They only needed to pump occasionally when there was sustained wet weather. (There were 2 further flooded 1km deep shafts and winding houses, vertically above each other, originally reaching down to over 3km, the deepest at the time.)
Stax
CC BY-SA 4.0
2018-05-16T04:11:15.440Z
2018-05-18T08:22:47.930Z
2018-05-18T08:22:47.930Z
jamesqf
<p>Since you termed it based on sea level, the gold mines in South Africa are not the deepest, they begin at an elevation of ~1500 m, meaning their 4 km depth is only 2.5 km below sea level.</p>

<p>The Kidd mine in Canada is 2.9 km deep and is located at an elevation of only ~250 m above sea level making it's depth 2.65 km below sea level.</p>

<p><a href="https://en.wikipedia.org/wiki/List_of_deepest_mines" rel="nofollow noreferrer">https://en.wikipedia.org/wiki/List_of_deepest_mines</a></p>

<p>Also if you don't care about the underground part and only care about below sea level, the undersea exploration of <A HREF="https://en.wikipedia.org/wiki/Challenger_Deep" rel="nofollow noreferrer">Challenger Deep</a> wins by a lot, they went ~12 km below sea level.</p>

CC BY-SA 4.0
2018-05-16T17:20:45.170Z
Ha. I don't think OP had open pit mines in mind. But their answer would be boring. :)
Mazura
CC BY-SA 4.0
2018-05-16T18:42:57.857Z
Correction, the Kidd mine is an underground mine, not open pit, but has a smaller open pit mine on the same site
Josh King
CC BY-SA 4.0
2018-05-17T07:00:44.300Z
The reference point for measurements makes a big difference in the results in questions like this.  Depth below surface vs depth below sea level vs distance from Earth's centre.  Thus, Chimborazo in Ecuador is higher than Mount Everest using the latter definition.
Vince O'Sullivan
CC BY-SA 4.0
2018-05-21T19:16:17.593Z
I suppose you could think of Challenger Deep as a really ambitious open pit mine as well...
Cort Ammon
CC BY-SA 4.0
2018-05-16T17:17:03.497Z
2018-05-18T02:30:03.627Z
2018-05-18T02:30:03.627Z
Josh King
<p>The book "Blind Descent" by James M. Tabor details this answer and I found it a terrific read.
I can't recall the exact depth, but what stuck in my mind was one particular explanation where the author said that we (humans) have gone as far below sea-level as above it. That is, roughly equivalent to the height of Everest - well over 8km.</p>

CC BY-SA 4.0
2018-05-17T13:04:58.583Z
As it stands I think this is quite a poor answer, but if you have the time to find the book and look up the details, it might be quite interesting!
Semidiurnal Simon
CC BY-SA 4.0
2018-05-18T02:39:42.793Z
Indeed, the exact details would help, but seems a fair answer.  However, of course that isn't including flight/rocketry, which seems unfair.
JeopardyTempest
CC BY-SA 4.0
2018-05-18T12:56:30.290Z
IMO any answer is a good answer. Don't be discouraged from here. I got massacred before I started to write good posts/answers/questions and still miss often.Try some of the other SE sites as well.
Muze
CC BY-SA 4.0
2018-05-17T06:41:18.237Z
2018-05-17T06:41:18.237Z
Liam
<p>I remember Journey to the Center of Earth and wonder: What is the deepest in the Earth surface or below sea level we have traveled either by foot, sub, drill or camera? </p>

CC BY-SA 4.0
2018-05-16T15:47:59.200Z
Also of interest to many may be [Can we really travel through earth's core?](https://earthscience.stackexchange.com/questions/246/can-we-really-travel-through-earths-core/454)
JeopardyTempest
CC BY-SA 4.0
2018-05-17T07:41:39.720Z
Now that you've changed what you're asking, the answer is surely the Mariana Trench, almost 11km below sea level.
curiousdannii
CC BY-SA 4.0
2018-05-17T13:04:14.637Z
Neither a drillbit in a borehole, nor a journey in a submarine, could possibly be described as "on foot"!
Semidiurnal Simon
CC BY-SA 4.0
2018-05-18T08:34:46.827Z
Oh come on. This question started off asking how far below the earth's surface people had gone on foot. Then it became how far below sea level on foot. Now it's just below sea level. Each time people have answered the question, and had their answer become wrong because the question has changed. PLEASE DO NOT DO THIS.
Semidiurnal Simon
CC BY-SA 4.0
2018-05-19T19:41:59.937Z
@muze But you are drastically changing the criteria of the answer, making assessing the quality of an answer impossible. just ask a new question if you are going to change it that much. Right now the Kola superdeep would be perfectly valid answer even though it is only 9 inches across.
John
<geography><mantle><crust><mining><cavern>
What is the deepest we have ever gone into the Earth?
Muze
# What is the deepest we have ever gone into the Earth?

(Asked by: username_0 on 2018-05-16)

I remember Journey to the Center of Earth and wonder: What is the deepest in the Earth surface or below sea level we have traveled either by foot, sub, drill or camera?

**Tags:** geography, mantle, crust, mining, cavern

> **Comments:**
> **username_1**: Also of interest to many may be [Can we really travel through earth's core?](https://earthscience.stackexchange.com/questions/246/can-we-really-travel-through-earths-core/454)  
> **username_2**: Now that you've changed what you're asking, the answer is surely the Mariana Trench, almost 11km below sea level.  
> **username_3**: Neither a drillbit in a borehole, nor a journey in a submarine, could possibly be described as "on foot"!  
> **username_3**: Oh come on. This question started off asking how far below the earth's surface people had gone on foot. Then it became how far below sea level on foot. Now it's just below sea level. Each time people have answered the question, and had their answer become wrong because the question has changed. PLEASE DO NOT DO THIS.  
> **username_4**: @username_0 But you are drastically changing the criteria of the answer, making assessing the quality of an answer impossible. just ask a new question if you are going to change it that much. Right now the Kola superdeep would be perfectly valid answer even though it is only 9 inches across.  

---

## 3 answers

### Answer by username_5 on 2018-05-16. Score: 31

Probably a bit over 4 km, in this South African mine: <https://en.wikipedia.org/wiki/Mponeng_Gold_Mine> But as the link mentions, the mine operators go to considerable lengths to reduce the mine temperature to endurable levels from the 66°C/151°F of the surrounding rock.

Note: This answer is for the original question, where the OP asked for the deepest depth below the surface. It's since been changed to ask for depth below sea level.

[![enter image description here](https://i.sstatic.net/VwkFT.jpg)](https://i.sstatic.net/VwkFT.jpg)

<http://cracked.tumblr.com/post/162183647834/the-mponeng-gold-mine-in-south-africa-is-the>

> **Comments:**
> **username_6**: How far below the surface is the natural water table at the mine? Because once the mine is eventually abandoned, when the recoverable gold has been mined, the pumps will be turned off & the mine will flood, which will reduce the depth that anyone could have access to while breathing air.  
> **username_7**: @username_6: But if it's abandoned, nobody will be down there anyway.  
> **username_6**: @username_7: Not necessarily. It may be abandoned by large mining companies for mining purposes but it could be re-purposed. Smaill scale illegal miners could attempt scavenging operations or it could be used for scientific purposes such as the former [Homestake Mine ](https://en.wikipedia.org/wiki/Homestake_experiment) which is housing an experiment to detect neutrinos produced by the Sun.  
> **username_7**: @username_6: Not if it's flooded ;)  
> **username_6**: The usable depth depends on the water table & how much of the mine is flooded.  
> **username_8**: There are so many mines along the 56 km long Witwatersrand gold reef in South Africa that the water levels in many abandoned mines is kept down by pumping in adjacent working mines. In the 1990's I went on a mine tour of one that that was abandoned in the 70s. We went to just short of the bottom of the first 1km deep shaft, where the water level was. They only needed to pump occasionally when there was sustained wet weather. (There were 2 further flooded 1km deep shafts and winding houses, vertically above each other, originally reaching down to over 3km, the deepest at the time.)  

---

### Answer by username_9 on 2018-05-16. Score: 19

Since you termed it based on sea level, the gold mines in South Africa are not the deepest, they begin at an elevation of ~1500 m, meaning their 4 km depth is only 2.5 km below sea level.

The Kidd mine in Canada is 2.9 km deep and is located at an elevation of only ~250 m above sea level making it's depth 2.65 km below sea level.

<https://en.wikipedia.org/wiki/List_of_deepest_mines>

Also if you don't care about the underground part and only care about below sea level, the undersea exploration of [Challenger Deep](https://en.wikipedia.org/wiki/Challenger_Deep) wins by a lot, they went ~12 km below sea level.

> **Comments:**
> **username_10**: Ha. I don't think OP had open pit mines in mind. But their answer would be boring. :)  
> **username_9**: Correction, the Kidd mine is an underground mine, not open pit, but has a smaller open pit mine on the same site  
> **username_11**: The reference point for measurements makes a big difference in the results in questions like this.  Depth below surface vs depth below sea level vs distance from Earth's centre.  Thus, Chimborazo in Ecuador is higher than Mount Everest using the latter definition.  
> **username_12**: I suppose you could think of Challenger Deep as a really ambitious open pit mine as well...  

---

### Answer by username_13 on 2018-05-17. Score: -2

The book "Blind Descent" by James M. Tabor details this answer and I found it a terrific read.
I can't recall the exact depth, but what stuck in my mind was one particular explanation where the author said that we (humans) have gone as far below sea-level as above it. That is, roughly equivalent to the height of Everest - well over 8km.

> **Comments:**
> **username_3**: As it stands I think this is quite a poor answer, but if you have the time to find the book and look up the details, it might be quite interesting!  
> **username_1**: Indeed, the exact details would help, but seems a fair answer.  However, of course that isn't including flight/rocketry, which seems unfair.  
> **username_0**: IMO any answer is a good answer. Don't be discouraged from here. I got massacred before I started to write good posts/answers/questions and still miss often.Try some of the other SE sites as well.  

---

