diff --git a/blog/sexp/sexp_components.py b/blog/sexp/sexp_components.py
index 7c22ccf..03ec763 100644
--- a/blog/sexp/sexp_components.py
+++ b/blog/sexp/sexp_components.py
@@ -148,7 +148,7 @@ def _post_admin_nav_html(ctx: dict) -> str:
     market_url_fn = ctx.get("market_url")
     if callable(events_url_fn):
         for url_fn, path, label in [
-            (events_url_fn, f"/{slug}/calendars/calendars/", "calendars"),
+            (events_url_fn, f"/{slug}/admin/", "calendars"),
             (market_url_fn, f"/{slug}/", "markets"),
             (events_url_fn, f"/{slug}/payments/", "payments"),
         ]:
diff --git a/events/app.py b/events/app.py
index cb5c082..09478a8 100644
--- a/events/app.py
+++ b/events/app.py
@@ -90,8 +90,8 @@ def create_app() -> "Quart":
         url_prefix="/<slug>",
     )
 
-    # Calendars nested under post slug: /<slug>/<calendar_slug>/...
-    # Listing stays at /<slug>/calendars/, individual at /<slug>/<calendar_slug>/
+    # Calendar admin under post slug: /<slug>/admin/
+    # Individual calendars at /<slug>/<calendar_slug>/
     app.register_blueprint(
         register_calendars(),
         url_prefix="/<slug>",
diff --git a/events/bp/calendars/routes.py b/events/bp/calendars/routes.py
index e4e26ab..53625b1 100644
--- a/events/bp/calendars/routes.py
+++ b/events/bp/calendars/routes.py
@@ -21,7 +21,7 @@ from shared.browser.app.utils.htmx import is_htmx_request
 
 
 def register():
-    bp = Blueprint("calendars", __name__, url_prefix='/calendars')
+    bp = Blueprint("calendars", __name__, url_prefix='/admin')
     bp.register_blueprint(
       register_calendar(),
     )
@@ -32,7 +32,7 @@ def register():
 
     # ---------- Pages ----------
 
-    @bp.get("/calendars/")
+    @bp.get("/")
     @cache_page(tag="calendars")
     async def home(**kwargs):
         from shared.sexp.page import get_template_context
@@ -46,7 +46,7 @@ def register():
         return await make_response(html)
 
 
-    @bp.post("/calendars/new/")
+    @bp.post("/new/")
     @require_admin
     @clear_cache(tag="calendars", tag_scope="all")
     async def create_calendar(**kwargs):
diff --git a/events/bp/calendars/services/calendars.py b/events/bp/calendars/services/calendars.py
index 3fb12d0..24d139c 100644
--- a/events/bp/calendars/services/calendars.py
+++ b/events/bp/calendars/services/calendars.py
@@ -86,7 +86,9 @@ async def create_calendar(sess: AsyncSession, post_id: int, name: str) -> Calend
     name = (name or "").strip()
     if not name:
         raise CalendarError("Calendar name must not be empty.")
-    slug=slugify(name)
+    slug = slugify(name)
+    if slug in ("admin", "markets", "payments", "entries"):
+        raise CalendarError(f'"{slug}" is a reserved name and cannot be used as a calendar name.')
 
     # Ensure post exists (avoid silent FK errors in some DBs)
     raw = await fetch_data("blog", "post-by-id", params={"id": post_id}, required=False)