Brown Moss of breeding birds at the site and many visitors, including wetland birds, such as Canada goose, mallard and great crested grebe. During the summer, froglets and dragonflies are found around water and woodland edges. Brown Moss is a flat site that was created at the end of the last Ice Age, over 10,000 years ago. As glaciers retreated, pools were formed by the stranded ice rocks, forming kettle holes Peat is still being created and Sphagnum moss – which is very important for the creation of peat – is found in abundance. This site contains a number of circular walks
Portlethen Moss have been enhanced by proximity to the sea and natural defensive protection of the moss to impede intruders. From Tacitus accounts of the Roman general Agricola, it is known that the Romans were daunted by Portlethen Moss, Netherley Red Moss, Cookney Moss and other local bogs that hindered travel. This is also evidenced by the Roman Camp of Raedykes having been established immediately south of this cluster of mosses; the Romans not being able to progress further north, turned inland toward Netherley.The Portlethen Moss is near the Grampian Mountains. The ancient Causey Mounth passage specifically connected the Bridge of Dee