Make EMACS Remember two Locations per Buffer

[Felix E. Klee]

Here is something that has annoyed me almost forever when using EMACS.
Is there a solution?

An example scenario:

1. I open a buffer.

2. I split the screen vertically: C-x 2

3. I work on the buffer, appreciating that I can compare two parts of
  it, one on the top, one on the bottom.

4. In the bottom window, I want to temporarily switch to another
buffer,
  and then return to the contents it was displaying before.
  Unfortunately, this is *not* possible! At least as far as I know...

  What is possible:

  a) I switch to another buffer.

  b) I switch back to the original buffer.

  c) I manually return to the location I was editing before.

Why isn't it possible for EMACS to remember that location? Or is it?