The JLE introduced radical engineering and architectural features that departed from the cramped, Victorian feel of older lines:
A lava tube is a natural conduit formed by flowing lava that moves beneath the hardened surface of a lava flow. When the lava within the conduit empties, a tunnel remains. They are common in shield volcanoes and are vital to understanding how volcanic islands grow. The Youngest Tubes in the World (As of 2026) youngest tube