Maybe black holes don’t lead anywhere. They just compact matter and energy into its lowest theoretical form. When that condition is reached and the ultimate packed field solid exists, it adds girth around as an accreting object with more material drawn unto itself.
The most tightly compacted state of matter and energy may be so much smaller by orders of magnitude than ordinary matter that any particular black hole might contain an entire galaxy or even hundreds or thousands of galaxies without trouble. Its gravity would be troubling to other mass and energy outside the event horizon of course.
Perhaps there is space-time lensing, comparable to gravity lensing, around a black hole. Because a hole is circular the space-time warp might let one get around to the other side of the black hole very quickly.
N.A.S.A. image of light being distorted around a black hole