Worldgates naturally occur in places with a high population density, or with a long history of population. They often form as complexes, in related groups.
Someone -- or some One -- knew what they were doing when the New York worldgate complex ended up in Grand Central Terminal.
On one fairly deserted platform, the air bends oddly, as through in heatwaves -- and Nita and Andrew step from
wood to concrete.
Nita turns and grins at her companion. "Welcome to New York."