As is nicely visualised by it's Penrose Diagram, e.g.
https://jila.colorado.edu/~ajsh/insidebh/penrose_schw.gif
Some PBS Space Time episodes featuring the Penrose Diagram (in order - the first two are from 9 years ago, the last from 6)
What Happens at the Event Horizon? - https://youtu.be/mht-1c4wc0Q
Escape The Kugelblitz Challenge - https://youtu.be/v3hd3AI2CAA
Mapping the Multiverse - https://youtu.be/4v9A9hQUcBQ
I enjoyed this Veritasium video on the subject, which includes Penrose Diagrams.
https://youtu.be/6akmv1bsz1M
Sorry man, that's not what this is about.
Some PBS Space Time episodes featuring the Penrose Diagram (in order - the first two are from 9 years ago, the last from 6)
What Happens at the Event Horizon? - https://youtu.be/mht-1c4wc0Q
Escape The Kugelblitz Challenge - https://youtu.be/v3hd3AI2CAA
Mapping the Multiverse - https://youtu.be/4v9A9hQUcBQ