Arthashastra
धान्वन वन संकट पङ्क शैल निम्न विषम नावो गावः शकटव्यूहो नीहारो रात्रिर् इति सत्त्राणि ॥
A desert, a dangerous spot, marshy places, mountains, valleys, uneven boats, cows, cart-like array of the army, mist, and night are sattras (temptations alluring the enemy against the invader).
english translation
dhAnvana vana saMkaTa paGka zaila nimna viSama nAvo gAvaH zakaTavyUho nIhAro rAtrir iti sattrANi ॥
hk transliteration by Sanscript