Welcome to Half-Life Answers. What would you like to know?

From the given pictures, most likely shortcuts to get to new test chambers. Appears to have catwalks, pipes, and vents. To get through those areas, I assume the ground or walls will be moved by GLaDOS.

Ad blocker interference detected!

Wikia is a free-to-use site that makes money from advertising. We have a modified experience for viewers using ad blockers

Wikia is not accessible if you’ve made further modifications. Remove the custom ad blocker rule(s) and the page will load as expected.