A line of hair, that runs down the center of a male's abdomen, from just below the belly button, down to the beginning of the pubic region.
In some instances, having a treasure trail is, in itself, a turn on for some men.
The path that leads to the ultimate treasure, the penis, is a common way many porn writers will describe the treasure trail.
Prominent feature many like to tend to, during foreplay. Letting their fingers run across the small tuft of hair, teasing the other, as they move down, towards the so-called 'promised land'.