Subscriptions / notifications question.

Here is what I would like to do with the site I'm working on:

We have pages with facility locations. Then we have pages that are events located at these facility locations. What I want end users to have the ability to do is to subscribe to receive e-mail notifications whenever new content is added that relates to these locations. I'd like to have this subscription capability present on each page that relates to each location.

So if we have, for example:

Location 1
-- Main page
-- Event 1
-- Event 2
-- Event 3

Location 2
-- Main page
-- Event 4
-- Event 5
-- Event 6

I'd like to have a subscription form on all of these pages. But the subscription form on Location 1 related pages would only provide notifications for content updates relating to location 1. Then the subscription form on Location 2 related pages would only provide notifications relating to location 2. I'd like these notifications to send A) whenever any of the pages related to each location are updated *and* B) whenever new pages are added to the site that are designated in some way as relating to that location. End-users would merely enter their e-mail address into a form to subscribe to receive these notifications.

What I'd like to find out is if there is a module or combination of modules anyone can recommend that would accomplish this and maybe some basic instructions if setting this up won't be obvious.

Thanks in advance for any advice anyone can offer.