diff --git a/activity/feeds.py b/activity/feeds.py
new file mode 100644
index 00000000..c5ff5a36
--- /dev/null
+++ b/activity/feeds.py
@@ -0,0 +1,95 @@
+import uuid
+from itertools import chain
+from operator import attrgetter
+
+from django.contrib.syndication.views import Feed
+from django.urls import reverse
+from django.utils.feedgenerator import Rss201rev2Feed
+
+
+from activity.models import (
+    GeoreferenceGroup,
+    SitewideMilestone,
+    SubjectIntroduction,
+    UserMilestone,
+    CollectionIntroduction,
+)
+
+MAX_ITEMS = 50
+
+
+class SitewideActivityFeed(Feed):
+    """
+    Site-wide RSS feed showing the latest georeferences, subjects, and milestones.
+    """
+    feed_type = Rss201rev2Feed
+    title = "Yesterdays - Site-wide Activity"
+    link = "/activity/"  # Update with your main activity page URL
+    description = "The latest georeferences subjects, and milestones in Yesterdays."
+
+    def items(self):
+        # Fetch the most recent items of each activity type.
+        georefs = GeoreferenceGroup.objects.all().order_by('-ended_at')[:MAX_ITEMS]
+        user_milestones = UserMilestone.objects.all().order_by('-reached_at')[:MAX_ITEMS]
+        sitewide_milestones = SitewideMilestone.objects.all().order_by('-created_at')[:MAX_ITEMS]
+        subjects = SubjectIntroduction.objects.all().order_by('-reached_at')[:MAX_ITEMS]
+        collections = CollectionIntroduction.objects.all().order_by('-created_at')[:MAX_ITEMS]
+
+        # Chain them together and sort chronologically
+        combined = sorted(
+            chain(georefs, subjects, user_milestones, sitewide_milestones, collections),
+            key=attrgetter('created_at', 'reached_at', 'ended_at'),
+            reverse=True,
+        )
+        return combined[:MAX_ITEMS]
+
+    def item_title(self, item):
+        if isinstance(item, GeoreferenceGroup):
+            return f"Images georeferenced by {getattr(item, 'user', 'a user')}"
+        elif isinstance(item, SubjectIntroduction):
+            return f"New subject added: {item.subject.title}"
+        elif isinstance(item, UserMilestone):
+            return f"{item.user.username} reached {item.count} georeferences!"
+        elif isinstance(item, SitewideMilestone):
+            return f"Yesterdays reached {item.count} images georeferenced!"
+        elif isinstance(item, CollectionIntroduction):
+            return f"New collection added: {item.collection.name}"
+        return str(item)
+
+    def item_description(self, item):
+        if isinstance(item, GeoreferenceGroup):
+            count = getattr(item, 'count', 'Multiple')
+            return f"{count} images were recently georeferenced."
+        elif isinstance(item, SubjectIntroduction):
+            return "A new subject was introduced to the catalog."
+        elif isinstance(item, UserMilestone):
+            return "A user has reached a new georeferencing milestone."
+        elif isinstance(item, SitewideMilestone):
+            return "The community has reached a new site-wide milestone."
+        elif isinstance(item, CollectionIntroduction):
+            return "A new collection was introduced to the catalog."
+        return str(item)
+
+    def item_link(self, item):
+        # Default to method if the model has one. Covers Image, Subject, Collection
+        if hasattr(item, 'get_absolute_url'):
+            return item.get_absolute_url()
+        elif isinstance(item, SubjectIntroduction):
+            return item.subject.get_absolute_url()
+        elif isinstance(item, UserMilestone):
+            return reverse("user_profile", kwargs={"username": item.user.username})
+        elif isinstance(item, CollectionIntroduction):
+            return item.collection.get_absolute_url()
+
+        # GeoreferenceGroup and SitewideMilestone go nowhere?
+        return "/activity/"
+
+    def item_pubdate(self, item):
+        return getattr(item, 'created_at', None) or getattr(item, 'reached_at', None) or getattr(item, 'ended_at', None)
+
+    def item_guid(self, item):
+        """
+        Set a random UUID for each item, so that the exact same session can appear in
+        multiple feeds if necessary and won't be filtered by RSS clients.
+        """
+        return str(uuid.uuid4())
diff --git a/activity/urls.py b/activity/urls.py
index 82045c86..2bed5cce 100644
--- a/activity/urls.py
+++ b/activity/urls.py
@@ -1,9 +1,11 @@
 from django.urls import path
 
-from . import views
+from activity import views
+from activity.feeds import SitewideActivityFeed
 
 app_name = "activity"
 
 urlpatterns = [
     path("", views.activity_feed, name="feed"),
+    path("feed/",SitewideActivityFeed(), name="site-feed")
 ]
diff --git a/api/tests.py b/api/tests.py
index c8d82075..ca294767 100644
--- a/api/tests.py
+++ b/api/tests.py
@@ -1108,3 +1108,41 @@ def test_cannot_revoke_other_users_consent(self):
         )
         self.assertEqual(resp.status_code, 404)
         self.assertTrue(ApplicationConsent.objects.filter(pk=consent.pk).exists())
+
+
+# ---------------------------------------------------------------------------
+# RSS Feeds
+# ---------------------------------------------------------------------------
+
+
+class TestSitewideActivityFeed(ApiFixturesMixin, TestCase):
+    def test_feed_status_and_type(self):
+        resp = self.client.get("/activity/feed/")
+        self.assertEqual(resp.status_code, 200)
+        self.assertEqual(resp["Content-Type"], "application/rss+xml; charset=utf-8")
+
+    def test_feed_content(self):
+        resp = self.client.get("/activity/feed/")
+        content = resp.content.decode("utf-8")
+        
+        self.assertIn('<rss version="2.0"', content)
+        self.assertIn("<title>Yesterdays - Site-wide Activity</title>", content)
+        # Based on the test fixtures, we should have a milestone in the activity feed
+        self.assertIn("milestone", content.lower())
+
+
+class TestSubjectActivityFeed(ApiFixturesMixin, TestCase):
+    def test_feed_status_and_type(self):
+        resp = self.client.get(f"/subjects/{self.subject.slug}/feed/")
+        self.assertEqual(resp.status_code, 200)
+        self.assertEqual(resp["Content-Type"], "application/rss+xml; charset=utf-8")
+
+    def test_feed_content(self):
+        resp = self.client.get(f"/subjects/{self.subject.slug}/feed/")
+        content = resp.content.decode("utf-8")
+        self.assertIn('<rss version="2.0"', content)
+        self.assertIn(self.img1.title, content)
+
+    def test_feed_404(self):
+        resp = self.client.get("/subjects/fake-subject/feed/")
+        self.assertEqual(resp.status_code, 404)
diff --git a/subjects/feeds.py b/subjects/feeds.py
new file mode 100644
index 00000000..bd10c198
--- /dev/null
+++ b/subjects/feeds.py
@@ -0,0 +1,54 @@
+import uuid
+
+from django.contrib.syndication.views import Feed
+from django.shortcuts import get_object_or_404
+from django.utils.feedgenerator import Rss201rev2Feed
+
+from images.models import Image
+from subjects.models import Subject
+
+class SubjectActivityFeed(Feed):
+    """
+    Subject-specific RSS feed showing new photos tagged with a given subject.
+    """
+    feed_type = Rss201rev2Feed
+
+    def get_object(self, request, subject_slug):
+        # Grabs the subject object when the URL is requested
+        return get_object_or_404(Subject, slug=subject_slug)
+
+    def title(self, subject):
+        return f"Yesterdays - New images for {subject.name}"
+
+    def link(self, subject):
+        return subject.get_absolute_url()
+
+    def description(self, subject):
+        return f"Latest images tagged with: {subject.name}."
+
+    def items(self, subject):
+        # Assuming SubjectMapping links Image and Subject via a ForeignKey to Subject.
+        # The related lookup name (`subjectmapping__subject`) might need to be tweaked
+        # depending on your exact ForeignKey setup in SubjectMapping.
+        return Image.objects.filter(
+            subjectmapping__subject=subject,
+        ).distinct().order_by('-created_at')[:50]
+
+    def item_title(self, image):
+        return f"New image tagged: {image.title}"
+
+    def item_description(self, image):
+        return image.description
+
+    def item_link(self, item):
+        return item.get_absolute_url()
+
+    def item_pubdate(self, image):
+        return image.created_at
+
+    def item_guid(self, subject):
+        """
+        Set a random UUID for each item, so that the exact same session can appear in
+        multiple feeds if necessary and won't be filtered by RSS clients.
+        """
+        return str(uuid.uuid4())
diff --git a/subjects/urls.py b/subjects/urls.py
index 5c05308d..d4c0a6b5 100644
--- a/subjects/urls.py
+++ b/subjects/urls.py
@@ -1,6 +1,7 @@
 from django.urls import path
 
-from . import views
+from subjects import views
+from subjects.feeds import SubjectActivityFeed
 
 app_name = "subjects"
 
@@ -9,6 +10,7 @@
     path("", views.browse_subjects, name="browse_subjects"),
     path("map/", views.subjects_map, name="subjects_map"),
     path("<slug:subject_slug>/", views.subject_detail, name="subject_detail"),
+    path("<slug:subject_slug>/feed/", SubjectActivityFeed(), name="subject_feed"),
     path(
         "<slug:subject_slug>/similar/",
         views.find_similar_images_to_subject,