Negative ions

Independent measurements in the Ravne tunnel network in Visoko

Since the discovery of the Bosnian Pyramid of the Sun in Visoko in 2005, the nearby Ravne underground tunnel system has gradually become known for its healing effects. Part of these healing powers are negative air ions, which have a positive effect on our health. Measurement results of the very high negative ion concentration in the tunnel sections are presented below.

Under the Bosnian Valley of the Pyramids, several underground tunnel systems have been discovered and partially cleared since 2005. The most famous and longest accessible labyrinth is the Ravne tunnel. This was almost completely filled with gravel sediment at the time of discovery. With the help of organic materials and radiocarbon dating, it was found that the tunnel system was sealed with gravel some 4500 to 5000 years ago. The tunnel system itself consists of conglomeratic rocks. Organic materials (pieces of wood in the conglomerate) in this material were also examined using the radiocarbon method. The calibrated calendar age of the underground labyrinth is approximately 34000 years. This suggests that two different cultures existed: One who built the complex network of underground passages, crossings, chambers and water accumulations, and those who closed the entire tunnel system with gravel.

Throughout the Ravne tunnel, the quality of the air is excellent. There is no pathogenic influence such as microorganisms, viruses, poisons or ionizing radiation that could cause disease. Breathing without difficulty is possible at any time in the underground labyrinth, no matter how far you are from the entrance. Test measurements of negative air ions were made in all sections of the tunnel system to locate the highest possible readings. Results at places with high concentrations and at interesting positions such as healing chambers, megaliths and sections near water are presented below.

Dr. Semir Osmanagić

Also known as Sam Osmanagich, he is Bosnia's best-known scientist, author on ancient civilizations and megalithic sites, independent researcher of pyramidal locations around the world, and director of the non-profit foundation 'Archaeological Park: Bosnian Pyramid of the Sun'. He became world famous for the discovery of the ancient pyramid complex in Visoko, consisting of five colossal pyramid objects and an accompanying network of prehistoric underground tunnels.

Underground labyrinth Ravne

The passages, intersections, chambers and water accumulations of the Ravne tunnel network that are already accessible are shown in color on the maze map according to the opening year. The whole tunnel system is divided into 3 routes. Route 1 is mainly used for touristic tours and includes interesting positions such as the egg-shaped monolith, the three ceramic blocks K1, K2 and K3 and the healing chamber. All tunnel corridors are equipped with many signs indicating the respective routes and the exit so that one cannot get lost. All three routes were taken into account for the measurement of negative ions.

Air Ion Counter 'AIC2'

The AIC2 handheld measuring device from AlphaLab Incorporated from the USA was used to measure the density of negative ions. It can measure the number of negative as well as positive ions per cubic centimeter in the air. This instrument is a true ion density meter based on a Gerdien tubular condenser and it contains a fan that lets the air flow through the meter. Its maximum measuring range of 200 million ions/ccm is more than adequate. Further setting options such as averaging rate, grounding, peak value mode, meter calibration and data recording characterize this handy measuring device.

Determination of measurement specification

In order to compare the ion concentration at different measurement locations, some measurement conditions are specified: At all measuring positions, the mean concentration of negative air ions is measured at a height of about 140 cm above the ground for 5 minutes. At least 5 measurements are carried out on different days for each measuring point. The arithmetic mean is then formed from these results. The set averaging rate is 14 seconds. The meter is not grounded because there was no difference to the earthed case during test measurements. A meter calibration is also performed before each daily measurement process.

Underground healing chamber

This chamber was discovered in 2010 and was completely covered with filler material. It is 50 sqm in size, 4 m high and located 220 m from the entrance. Due to the fact that 8 side tunnels are connected to this room, it serves as a kind of connection or meeting point. The measured average ion concentration is 44000 ions/ccm. This high amount of negative ions purifies the air, destroys viruses and bacteria, which means that this large healing chamber can be ideally used as a place to refresh the organism.

Exceptional volatility of ion density near water

Throughout all measurements, one position near water was particularly noticeable due to its above-average volatility of ion concentration values. This location is along route 2 at a distance of 315 m from the entrance. Although the average ion density here is 48000 ions/ccm, the maximum value was determined to be almost 80000 ions/ccm. At no other point in the tunnel system, such a high peak value has been measured so far. Whether the influence of the water alone or other factors are the reason for the high degree of concentration fluctuations remains unclear for the time being.

Meditation chamber (route 2)

At the end of route 2, at a distance of 340 m from the entrance, there is a spacious recreation room 14 m long, 2 m wide, 2.7 m high and equipped with numerous mounted wooden benches. The measured average concentration of negative ions here is 45000 ions/ccm. Such a high amount of ions also corresponds to a significant source of energy for our body. This large mediation chamber offers numerous visitors the opportunity to supply an enormous amount of "vitamins from the air" to the body and thus help to achieve even more energy.


Comprehensive independent measurements of the mean concentration of negative air ions in the Ravne underground labyrinth have shown that enormously high ion levels are found in the entire tunnel system. Here we are talking about a considerable factor of 90 to 160 compared to usual values of around 300 ions/ccm in a big city apartment.

Due to these high amounts of negative ions, stays in the labyrinth have very positive effects on the health of the human body. In the literature there are many studies and detailed descriptions of how negative ions affect the organism. In short, it can be said that negative ions support the immune system and cellular function (reduction of oxygen-based free radicals in the body), alleviate asthmatic and allergic complaints, improve metabolism, reduce acidity in the blood (blood purification), promote the emergence of alpha waves in the brain (relaxation, creative thoughts and feelings of happiness), as well as eliminate unwanted particles (harmful bacteria, viruses, funguses, pollen, dust) from the air. At this point, I would also like to point out the official Youtube channel of the foundation 'BosnianPyramidsTV' which provides much information about the tunnel complex, as well as a lot of positive experience contributions from numerous visitors about their improvement of health complaints as a result of longer stays in the underground labyrinth.

In conclusion, it can be summarized that the Ravne tunnel system is an energetically positive place to which a vitalizing and healing effect can be attributed thanks to the excessively high density of negative ions. From this point of view alone, the underground labyrinth in Visoko is a highly recommended health resort and should be visited several times for your own health care.


You have questions, further ideas or other suggestions? Feel free to contact me.

Emir Pireci

Manufacturing Engineer

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