Verses with the word bulwarks in the Old Testament (5 verses):

Deuteronomy 20:20
Only the trees which thou knowest that they be not trees for meat, thou shalt destroy and cut them down; and thou shalt build bulwarks against the city that maketh war with thee, until it be subdued.

2 Chronicles 26:15
And he made in Jerusalem engines, invented by cunning men, to be on the towers and upon the bulwarks, to shoot arrows and great stones withal. And his name spread far abroad; for he was marvellously helped, till he was strong.

Psalms 48:13
Mark ye well her bulwarks, consider her palaces; that ye may tell it to the generation following.

Ecclesiastes 9:14
There was a little city, and few men within it; and there came a great king against it, and besieged it, and built great bulwarks against it:

Isaiah 26:1
In that day shall this song be sung in the land of Judah; We have a strong city; salvation will God appoint for walls and bulwarks.