DR JUERG ALEAN / SCIENCE PHOTO LIBRARY DR JUERG ALEAN / SCIENCE PHOTO LIBRARY
Lava tube near Sao Vicente, Madeira. Lava tubes are formed when lava flows solidify on their surface and lava remaining fluid in their interior drains away. The lava tubes in Lava tube near Sao Vicente are open to visiting tourists. Some small lava stalactites hang from the roof.
Model release not required. Property release not required.