- The Lost City of Atlantis: A mythical island civilization described by Plato, whose existence and location remain unconfirmed.
- The Nazca Lines: A series of geoglyphs in the desert of Peru, including depictions of animals and plants, that are only visible from a distance or the air.
- Stonehenge: A prehistoric monument in England whose exact purpose and the method of moving the massive stones are still debated by experts.
- The Tunguska Event: A massive explosion that occurred in Siberia in 1908, flattening millions of trees but leaving no impact crater.
- The Dyatlov Pass Incident: The strange and fatal event in which nine hikers died in the Ural Mountains in 1959, with their tent found ripped open from the inside.
Scientific and cosmic mysteries
- Dark matter and dark energy: The majority of the universe is composed of these invisible substances, the nature of which is still not understood.
- The Fermi Paradox: The contradiction between the high probability of the existence of extraterrestrial civilizations and the lack of evidence for them.
- Animal migration: The precise and consistent routes that many species undertake, often over vast distances, remain an enigma.
- Quantum entanglement: A phenomenon in which particles become interconnected and affect each other instantly, regardless of distance, with implications for our understanding of reality that are not fully grasped.
Paranormal and unsolved cases
- The Bermuda Triangle: A region in the western part of the North Atlantic Ocean notorious for the unexplained disappearance of ships and aircraft.
- The Zodiac Killer: An unidentified serial killer who was active in the late 1960s and early 1970s.
- The "Wow!" Signal: A powerful, narrowband radio signal from space detected in 1977 that has never been repeated