Bible Verses About Towers: Watchmen posted on, in times of danger

Now the watchman was standing on the tower in Jezreel, and he spied the company of Jehu as he came, and said, I see a company. And Joram said, Take a horseman, and send to meet them, and let him say, Is it peace?

I will stand upon my watch, and set me upon the tower, and will look forth to see what he will speak with me, and what I shall answer concerning my complaint.