(1.5) How to access archives.php and not archive.php

There seems to be two files, one called archive.php and the other called archives.php, in the default style. The difference between the two seems to be the following:
archives.php – prints out a list of all archives by month and by subject
archive.php – is the standard archive page

I would like to figure out how to access the first file. I want a list of all the archives by month and by subject. However, I can not seem to figure out how to access the page. When I put in a URL of
https://www.foo.com/archives/ I get the second template. If I try to enter https://www.foo.com/archives.php I get a 404.

How do I access the first file – the one that lists the archive?