The Giant Underground Spider City Scientists Never Expected

Researchers have uncovered what may be the largest spider web ever documented—an enormous arachnid “supercity” hidden inside Sulfur Cave on the Greek–Albanian border.

First discovered in 2022 and studied for years, the web spans more than 100 square meters and is home to roughly 110,000 spiders belonging to two genetically distinct species unlike any found above ground.

Even more astonishing, species that normally live and hunt alone are forming colonies inside the cave for the first time ever recorded.

Scientists believe the cave’s massive population of midges provides a steady food source, allowing this unique underground ecosystem to flourish in complete darkness.

The discovery challenges long-held assumptions about spider behavior and reveals how extreme environments can reshape evolution.