diff --git a/location/__init__.py b/location/__init__.py
index d28ada2..f521011 100644
--- a/location/__init__.py
+++ b/location/__init__.py
@@ -1,7 +1,66 @@
+from typing import NamedTuple, Iterator, List, Iterable
+from datetime import datetime
 import logging
+import csv
+import geopy.distance # type: ignore
 
 def get_logger():
     return logging.getLogger("location")
 
+PATH = "/L/data/location/location.csv"
+CACHE_PATH = "/L/.cache/location.cache"
 
 # TODO need to cache?
+# TODO tag??
+
+Tag = str
+
+class Location(NamedTuple):
+    dt: datetime
+    lat: float
+    lon: float
+    tag: Tag
+
+
+def tagger(dt: datetime, lat: float, lon: float) -> Tag:
+    TAGS = [
+ # removed
+    ]
+    for coord, dist, tag in TAGS:
+        if geopy.distance.distance(coord, (lat, lon)).m  < dist:
+            return tag
+    else:
+        return "other"
+
+def iter_locations() -> Iterator[Location]:
+    with open(PATH) as fo:
+        reader = csv.reader(fo)
+        next(reader) # skip header
+        for ll in reader:
+            [ts, lats, lons] = ll
+            # TODO hmm, is it local??
+            dt = datetime.strptime(ts, "%Y-%m-%d %H:%M:%S")
+            lat = float(lats)
+            lon = float(lons)
+            tag = tagger(dt, lat, lon)
+            yield Location(
+                dt=dt,
+                lat=lat,
+                lon=lon,
+                tag=tag
+            )
+
+def get_locations(cached: bool=False) -> Iterable[Location]:
+    import dill # type: ignore
+    if cached:
+        with open(CACHE_PATH, 'rb') as fo:
+            preph = dill.load(fo)
+            return [Location(**p._asdict()) for p in preph] # meh. but otherwise it's not serialising methods...
+    else:
+        return list(iter_locations())
+
+def update_cache():
+    import dill # type: ignore
+    datas = get_locations(cached=False)
+    with open(CACHE_PATH, 'wb') as fo:
+        dill.dump(datas, fo)
diff --git a/location/__main__.py b/location/__main__.py
index e4da5b9..10a27dc 100644
--- a/location/__main__.py
+++ b/location/__main__.py
@@ -1,4 +1,4 @@
-from location import get_logger
+from location import get_logger, get_locations, iter_locations
 
 logger = get_logger()
 
@@ -6,5 +6,18 @@ from kython.logging import setup_logzero
 
 setup_logzero(logger)
 
+import sys
 
-
+if len(sys.argv) > 1:
+    cmd = sys.argv[1]
+    if cmd == "update_cache":
+        from location import update_cache, get_locations
+        update_cache()
+        get_locations(cached=True)
+    else:
+        raise RuntimeError(f"Unknown command {cmd}")
+else:
+    for p in iter_locations():
+        pass
+        # TODO need datetime!
+        # print(p)
diff --git a/update_cache b/update_cache
index 6daf62c..3938289 100755
--- a/update_cache
+++ b/update_cache
@@ -3,5 +3,5 @@ set -eu
 
 cd "$(dirname "$0")"
 
-python3 -m photos update_cache
+python3 -m location update_cache