The following sources were consulted in the preparation of the article “9 entrances to hell you can actually visit.”
- Darvaza Gas Crater
- Ancient Roman “Gate to Hell” Killed Victims With This Deadly Lake
- Masaya National Park
- Hekla – The Gateway to Hell
- Lake Avernus
- Cape Tainaron: Gateway to the Underworld
- Nekromanteion
- Actun Tunichil Muknal (ATM)
- Into the Centipede’s Jaws: Sumptuous Offerings from the Sacred Cenote at Chichén Itzá