diff --git a/LICENCE b/LICENCE
--- a/LICENCE
+++ b/LICENCE
@@ -1,4 +1,4 @@
-Copyright 2013-2014 NICTA Pty Ltd
+Copyright 2013-2014 NICTA Limited
 
 All rights reserved.
 
diff --git a/changelog b/changelog
--- a/changelog
+++ b/changelog
@@ -1,3 +1,11 @@
+0.0.17
+
+* Include prisms for radians. Requires a dependency on the `radian` package.
+
+0.0.16
+
+* Some minor fixes to the documentation.
+
 0.0.15
 
 * Change mod functions to use rem.
diff --git a/coordinate.cabal b/coordinate.cabal
--- a/coordinate.cabal
+++ b/coordinate.cabal
@@ -1,10 +1,10 @@
 name:               coordinate
-version:            0.0.16
+version:            0.0.17
 license:            BSD3
 license-file:       LICENCE
 author:             Tony Morris <ʇǝu˙sıɹɹoɯʇ@ןןǝʞsɐɥ>
 maintainer:         Tony Morris
-copyright:          Copyright (C) 2013-2014 NICTA Pty Ltd
+copyright:          Copyright (C) 2013-2014 NICTA Limited
 synopsis:           A representation of latitude and longitude
 category:           Development
 description:       
@@ -33,6 +33,7 @@
                     , lens >= 4.0
                     , tagged >= 0.7
                     , transformers >= 0.3.0.0
+                    , radian >= 0.0.1
 
   ghc-options:
                     -Wall
diff --git a/src/Data/Geo/Coordinate/DegreesLatitude.hs b/src/Data/Geo/Coordinate/DegreesLatitude.hs
--- a/src/Data/Geo/Coordinate/DegreesLatitude.hs
+++ b/src/Data/Geo/Coordinate/DegreesLatitude.hs
@@ -64,7 +64,7 @@
                then Just (DegreesLatitude i)
                else Nothing)
 
--- | Setting a value `>= 90` will get that value `(`rem` 90)`.
+-- | Setting a value @>= 90@ will get that value @(`rem` 90)@.
 --
 -- >>> remDegreesLatitude 7
 -- DegreesLatitude 7
diff --git a/src/Data/Geo/Coordinate/DegreesLongitude.hs b/src/Data/Geo/Coordinate/DegreesLongitude.hs
--- a/src/Data/Geo/Coordinate/DegreesLongitude.hs
+++ b/src/Data/Geo/Coordinate/DegreesLongitude.hs
@@ -64,7 +64,7 @@
                then Just (DegreesLongitude i)
                else Nothing)
 
--- | Setting a value `>= 180` will get that value `(`rem` 180)`.
+-- | Setting a value @>= 180@ will get that value @(`rem` 180)@.
 --
 -- >>> remDegreesLongitude 7
 -- DegreesLongitude 7
diff --git a/src/Data/Geo/Coordinate/Latitude.hs b/src/Data/Geo/Coordinate/Latitude.hs
--- a/src/Data/Geo/Coordinate/Latitude.hs
+++ b/src/Data/Geo/Coordinate/Latitude.hs
@@ -9,7 +9,7 @@
 ) where
 
 import Control.Applicative(Applicative)
-import Control.Category(Category(id))
+import Control.Category(Category(id, (.)))
 import Control.Lens(Choice, Profunctor, Optic', iso, prism', lens, (#), (^?))
 import Control.Monad(Monad(return))
 import Data.Eq(Eq)
@@ -18,6 +18,7 @@
 import Data.Geo.Coordinate.Minutes(AsMinutes(_Minutes), Minutes)
 import Data.Geo.Coordinate.Seconds(AsSeconds(_Seconds), Seconds)
 import Data.Ord(Ord((<)))
+import Data.Radian(Radian, radians)
 import Prelude(Double, Show, Int, Num((+), (*), (-), abs), Fractional((/)), properFraction, fromIntegral)
 
 -- $setup
@@ -123,6 +124,35 @@
                  m' <- (abs m :: Int) ^? _Minutes
                  s' <- (abs s * 60) ^? _Seconds
                  return (Latitude d' m' s'))
+
+-- | A prism on latitude to a double between -π2 and π2 exclusive. 
+--
+-- >>> (0.2 :: Radian Double) ^? _Latitude
+-- Just (Latitude (DegreesLatitude 11) (Minutes 27) (Seconds 32.9612))
+--
+-- >>> (1.3 :: Radian Double) ^? _Latitude
+-- Just (Latitude (DegreesLatitude 74) (Minutes 29) (Seconds 4.2481))
+--
+-- >>> (-1.3 :: Radian Double) ^? _Latitude
+-- Just (Latitude (DegreesLatitude (-74)) (Minutes 29) (Seconds 4.2481))
+--
+-- >>> (1.5707963 :: Radian Double) ^? _Latitude
+-- Just (Latitude (DegreesLatitude 89) (Minutes 59) (Seconds 59.9945))
+--
+-- >>> (1.58 :: Radian Double) ^? _Latitude
+-- Nothing
+--
+-- >>> (-1.58 :: Radian Double) ^? _Latitude
+-- Nothing
+--
+-- >>> fmap (\x -> _Latitude # x  :: Radian Double) (do deg <- (7 :: Int) ^? _DegreesLatitude; min <- (7 :: Int) ^? _Minutes; sec <- (7 :: Double) ^? _Seconds; (deg, min, sec) ^? _Latitude :: Maybe Latitude)
+-- Just (Radian 0.12424320205794079)
+--
+-- >>> fmap (\x -> _Latitude # x  :: Radian Double) (do deg <- (89 :: Int) ^? _DegreesLatitude; min <- (15 :: Int) ^? _Minutes; sec <- (6 :: Double) ^? _Seconds; (deg, min, sec) ^? _Latitude :: Maybe Latitude)
+-- Just (Radian 1.5577354462258055)
+instance (Choice p, Applicative f) => AsLatitude p f (Radian Double) where
+  _Latitude =
+    radians . _Latitude
 
 instance (p ~ (->), Functor f) => AsDegreesLatitude p f Latitude where
   _DegreesLatitude =
diff --git a/src/Data/Geo/Coordinate/Longitude.hs b/src/Data/Geo/Coordinate/Longitude.hs
--- a/src/Data/Geo/Coordinate/Longitude.hs
+++ b/src/Data/Geo/Coordinate/Longitude.hs
@@ -9,7 +9,7 @@
 ) where
 
 import Control.Applicative(Applicative)
-import Control.Category(Category(id))
+import Control.Category(Category(id, (.)))
 import Control.Lens(Choice, Profunctor, Optic', iso, prism', lens, (#), (^?))
 import Control.Monad(Monad(return))
 import Data.Eq(Eq)
@@ -18,6 +18,7 @@
 import Data.Geo.Coordinate.Minutes(AsMinutes(_Minutes), Minutes)
 import Data.Geo.Coordinate.Seconds(AsSeconds(_Seconds), Seconds)
 import Data.Ord(Ord((<)))
+import Data.Radian(Radian, radians)
 import Prelude(Double, Show, Int, Num((+), (*), (-), abs), Fractional((/)), properFraction, fromIntegral)
 
 -- $setup
@@ -123,6 +124,35 @@
                    m' <- (abs m :: Int) ^? _Minutes
                    s' <- (abs s * 60) ^? _Seconds
                    return (Longitude d' m' s'))
+
+-- | A prism on longitude to a double between -π and π exclusive.
+--
+-- >>> (0.2 :: Radian Double) ^? _Longitude
+-- Just (Longitude (DegreesLongitude 11) (Minutes 27) (Seconds 32.9612))
+--
+-- >>> (1.3 :: Radian Double) ^? _Longitude
+-- Just (Longitude (DegreesLongitude 74) (Minutes 29) (Seconds 4.2481))
+--
+-- >>> (-1.3 :: Radian Double) ^? _Longitude
+-- Just (Longitude (DegreesLongitude (-74)) (Minutes 29) (Seconds 4.2481))
+--
+-- >>> (3.14159 :: Radian Double) ^? _Longitude
+-- Just (Longitude (DegreesLongitude 179) (Minutes 59) (Seconds 59.4527))
+--
+-- >>> (3.15 :: Radian Double) ^? _Longitude
+-- Nothing
+--
+-- >>> (-3.15 :: Radian Double) ^? _Longitude
+-- Nothing
+--
+-- >>> fmap (\x -> _Longitude # x :: Radian Double) (do deg <- (7 :: Int) ^? _DegreesLongitude; min <- (7 :: Int) ^? _Minutes; sec <- (7 :: Double) ^? _Seconds; (deg, min, sec) ^? _Longitude :: Maybe Longitude)
+-- Just (Radian 0.12424320205794079)
+--
+-- >>> fmap (\x -> _Longitude # x :: Radian Double) (do deg <- (179 :: Int) ^? _DegreesLongitude; min <- (15 :: Int) ^? _Minutes; sec <- (6 :: Double) ^? _Seconds; (deg, min, sec) ^? _Longitude :: Maybe Longitude)
+-- Just (Radian 3.1285317730207023)
+instance (Choice p, Applicative f) => AsLongitude p f (Radian Double) where
+  _Longitude =
+    radians . _Longitude
 
 instance (p ~ (->), Functor f) => AsDegreesLongitude p f Longitude where
   _DegreesLongitude =
diff --git a/src/Data/Geo/Coordinate/Minutes.hs b/src/Data/Geo/Coordinate/Minutes.hs
--- a/src/Data/Geo/Coordinate/Minutes.hs
+++ b/src/Data/Geo/Coordinate/Minutes.hs
@@ -58,7 +58,7 @@
                then Just (Minutes i)
                else Nothing)       
 
--- | Setting a value `>= 60` will get that value `(`rem` 60)`.
+-- | Setting a value @>= 60@ will get that value @(`rem` 60)@.
 --
 -- >>> remMinutes 7
 -- Minutes 7
diff --git a/src/Data/Geo/Coordinate/Seconds.hs b/src/Data/Geo/Coordinate/Seconds.hs
--- a/src/Data/Geo/Coordinate/Seconds.hs
+++ b/src/Data/Geo/Coordinate/Seconds.hs
@@ -71,7 +71,7 @@
                then Just (Seconds d)
                else Nothing)
 
--- | Setting a value `>= 60` will get that value `(`rem` 60)`.
+-- | Setting a value @>= 60@ will get that value @(`rem` 60)@.
 --
 -- >>> remSeconds 7
 -- Seconds 7.0000