Holy Land Tunnel, Rock of Gibraltar
1840s underground tuberculosis hospital hut (Mammoth Cave, Kentucky, USA) 6
St. George's Hall, Rock of Gibraltar
1840s underground tuberculosis hospital hut (Mammoth Cave, Kentucky, USA) 8
Great Siege Tunnel, Rock of Gibraltar
Breakdown (Giant's Coffin, Main Cave, Mammoth Cave, Kentucky, USA) 1
Breakdown (Giant's Coffin, Main Cave, Mammoth Cave, Kentucky, USA) 16
Breakdown (Giant's Coffin, Main Cave, Mammoth Cave, Kentucky, USA) 4
1840s underground tuberculosis hospital hut (Mammoth Cave, Kentucky, USA) 7
Corpse Rock (Mammoth Cave, Kentucky, USA)
1840s underground tuberculosis hospital hut (Mammoth Cave, Kentucky, USA) 3
Breakdown (Giant's Coffin, Main Cave, Mammoth Cave, Kentucky, USA) 15
Breakdown (Giant's Coffin, Main Cave, Mammoth Cave, Kentucky, USA) 13
Acute Angle (Main Cave, Mammoth Cave, Kentucky, USA) 4
Breakdown (Giant's Coffin, Main Cave, Mammoth Cave, Kentucky, USA) 6
Breakdown (Giant's Coffin, Main Cave, Mammoth Cave, Kentucky, USA) 12
Breakdown (Giant's Coffin, Main Cave, Mammoth Cave, Kentucky, USA) 9