Ten articles concerning Senkojutsu.

One. Know the circumstances (i.e., layout and position) concerning the enclosure and structures of the enemyﾕs castle. Think thoroughly about ways to enter and retreat a territory, and devise methods [for that purpose]. That is, travel to castle areas in various provinces, by taking roads that merchants use, and during an hour when it is tranquil.
Think how to find an opportunity to enter and depart a territory deceitfully.

Moreover, you should draw a map (of the territory) using creativity and all means available to you. To [further] illustrate this point, when even the roads are unknown, enter the province and its villages, and familiarize yourself with the fields and roads. [Learn] which areas are steep, which areas are wide open, and [measure] the width of roads.