Walking some of my favorite cities, I have run into potential space-time gates, portals, rabbit holes or wormholes. These gates seem to have a common shape and design, pretty modernist and inspired the Art Nouveau aesthetic movement. They were originally designed by Hector Guimard. Here is one at the city of Chicago, at Michigan Aveneu train station:
Here is another one at the city of Mexico Distrito Federal, en la estación de Bellas Artes:
And here is one at the Paris’ metropolitain station Denfert-Rochereau:
