The Fortification - The Essentials of a State - WEALTH - Tirukkural

741
A fort is wealth to those who act against their foes;
Is wealth to them who, fearing, guard themselves from woes.
A fort is an object of importance to those who march (against their foes) as well as to those who through fear (of pursuers) would seek it for shelter.

742
A fort is that which owns fount of waters crystal clear,
An open space, a hill, and shade of beauteous forest near.
A fort is that which has everlasting water, plains, mountains and cool shady forests.

743
Height, breadth, strength, difficult access:
Science declares a fort must these possess.
The learned say that a fortress is an enclosure having these four (qualities) viz., height, breadth, strength and inaccessibility.

744
A fort must need but slight defence, yet ample be,
Defying all the foeman's energy.
A fort is that which has an extensive space within, but only small places to be guarded, and such as can destroy the courage of besieging foes.

745
Impregnable, containing ample stores of food,
A fort for those within, must be a warlike station good.
A fort is that which cannot be captured, which abounds in suitable provisions, and affords a position of easy defence to its inmates.

746
A fort, with all munitions amply stored,
In time of need should good reserves afford.
A fort is that which has all (needful) things, and excellent heroes that can help it against destruction (by foes).

747
A fort should be impregnable to foes who gird it round,
Or aim there darts from far, or mine beneath the ground.
A fort is that which cannot be captured by blockading, assaulting, or undermining it.

748
Howe'er the circling foe may strive access to win,
A fort should give the victory to those who guard within.
That is a fort whose inmates are able to overcome without losing their ground, even abler men who have besieged it.

749
At outset of the strife a fort should foes dismay;
And greatness gain by deeds in every glorious day.
A fort is that which derives excellence from the stratagems made (by its inmates) to defeat their enemies in the battlefield.

750
Howe'er majestic castled walls may rise,
To craven souls no fortress strength supplies.
Although a fort may possess all (the above-said) excellence, it is, as it were without these, if its inmates possess not the excellence of action.