On the Euphrates River, Hīt is a small walled town built on two mounds on the site of the ancient city of Is. In ancient times, the town was known for its bitumen wells, which were used as far back as 3,000 years ago, to include building of Babylon and for caulking boats. Hīt also became a frontier fortress for Assyria. Now, Hīt is a marketplace for agricultural produce and oil pipelines to the Mediterranean Sea cross the Euphrates there. It was regarded as the head of navigation on the river before the decline in river traffic. Hit marks the beginning of the high sedimentary plain on the Euphrates, and it contains a number of hot springs.