+way[boundary] { color: #000066; width: 2; opacity: 0.6; dashes: 24,4, 4, 4; z-index: 4;}
+/* Perhaps should be filled, on lower zooms. */
+way[boundary=national_park] { color: #225500; width: 2; opacity: 0.6; dashes: 24,4, 4, 4; z-index: 4;}
+way[boundary=protected_area] { color: #447744; width: 2; opacity: 0.6; dashes: 12,4, 4, 4; z-index: 4;}