Drystane dykes, many of which date back to Victorian times, remain an characteristic feature of the Perthshire and Angus glens. It is interesting to compare different styles of dyke, which depended on the type of stone available, the purpose of the dyke, and the skill of the particular dyker. While modern post-and-wire fences have to be replaced on a regular basis, a well-built dyke can last for hundreds of years. The gaps between the stones mean that dykes are often important wildlife habitats.