The Bog is populated with swamplurks, mirelurk hunters and swamplurk queens, all of which are found along the path towards the Mother Punga, a very large variant of the punga plant. Many punga plants can be found here, including 35 punga plants around the Mother Punga alone.
Directly North of the Sacred Bog Entrance is a burned out house with some loot.
The water inside the Sacred Bog has unusually low levels of radiation; drinking from most bodies of water inside the bog will heal 20 HP while only causing an increase of 1 unit of radiation. The exception is the body of water immediately prior to the Mother Punga plant, which has a normal level of radiation.
Upon entering this location, fast travel is not available until you exit from sacred bog entrance.
pcxbox360 There are reports of unusually frequent crashes in this area on PC as well as the Xbox 360. Upon investigating in the GECK, there is an activator in this cell that can cause some PCs to crash. There is a third party fix available.
ps3 There is a possible bug that will allow you to remain under the swamp water just outside of the Sacred Bog Entrance without affecting oxygen levels.