A cat may systematically move around the boundary of a portion of its territory, this is known as patrolling. In most cases the gait will vary between a walk and a trot and the cat may also stand or sit at various points to passively explore the environment or investigate a specific object, by both visual and olfactory means (i.e. sniffing). It is common for some cats, particularly entire males, to spray urine at specific sites on their patrol route and to sniff previously deposited urine marks.
On the following video the path that the cat habitually patrols has been marked in red. You will see him walk the route and also stop near to a previously deposited urine mark (circled in red).