Geometry of transit
Certain portals can only be opened with a series of specific gestures, often defined by peculiar symbols inscribed nearby.
Painted this picture of a Yordle Gateway while working in collaboration with Maisie : https://www.artstation.com/whren
More Yordle Gateways concept art:
https://www.artstation.com/artwork/NAzwq
https://www.artstation.com/artwork/eAqAZ