Of course, the city met its' end about two hundred years after Jonah made his trip there. The city was destroyed and basically was forgotten about except for Biblical references. It wasn't until the 1800s that the city was unearthed and much has been learned about it since then. One of the things of note was that the walls of the city were wide enough that three chariots could ride abreast of each other. Just the enormity of the walls is enough to impress any casual observer.
The city was so wicked in its' heyday that Jonah didn't want to go there. So much so, that he took off for parts unknown. But, one cannot escape God's watchful eye. In God's opinion, Jonah was the man for the job. And, after some strong convincing, Jonah decided he would go. So, for a second time, God says "Arise, go unto Nineveh, that great city, and preach unto it the preaching that I bid thee." (Jonah 3:2) So he goes, enters the city and says, "Yet forty days, and Nineveh shall be overthrown." (Jonah 3:4)
The message is still the same. It's important to cry against sin. God is long suffering. He's not willing that any should perish. (II Peter 3:9) Get started on what God wants. Determine, like Paul, to "know nothing, save Jesus Christ, and him crucified." (I Corinthians 2:2) Three times it says in Mark 9 "Where their worm dieth not, and the fire is not quenched." (verse 44,46,48) Hell burns hot and like Pastor Josh says, "There are no fire extinguishers in hell."
Man in the parking lot speaking to Pastor Josh saying that the devil is working overtime. Pastor Josh's reply was "Yes, but God's not on vacation. He is still in charge. God will make it right someday. We know that he is the judge."
Nineveh was on God's radar. Sin was about to be judged. God sent Jonah to cry against sin. God had a message because they were people, not heathens. Be for Jesus and against sin. After all, there ain't no fire extinguishers in hell.