In 1845–47 and again in 1849–51 Mr. (later Sir) A. H. Layard carried out a series of excavations among the ruins of the ancient city of Nineveh, "that great city, wherein are more than sixteen thousand persons that cannot discern between their right hand and their left; and also much cattle" (Jonah iv, II). Its ruins lie on the left or east bank of the Tigris, exactly opposite the town of Al-Mawsil, or Môsul, which was founded by the Sassanians and marks the site of Western Nineveh. At first Layard thought that these ruins were not those of Nineveh, which he placed at Nimrûd, about 20 miles downstream, but of one of the other cities that were builded by Asshur (see Gen. x, 11, 12). Thanks, however, to Christian, Roman and Muhammadan tradition, there is no room for doubt about it, and the site of Nineveh has always been known. The fortress which the Arabs built there in the seventh century was known as "Kal'at-Nînawî, i.e., "Nineveh Castle," for many centuries, and all the Arab geographers agree in saying that tile mounds opposite Môsul contain the ruins of the palaces and walls of Nineveh. And few of them fail to mention that close by them is "Tall Nabi Yûnis," i.e., the Hill from which the Prophet Jonah preached repentance to the inhabitants of Nineveh, that "exceeding great city of three days' journey" (Jonah iii, 3). Local tradition also declares that the prophet was buried in the Hill, and his supposed tomb is shown there to this day.
The Walls and Palaces of Nineveh.
The situation of the ruins of the palaces of Nineveh is well shown by the accompanying reproduction of the plan of the city made by Commander Felix Jones, I.N. The remains of the older palaces built by Sargon II (B.C. 721–705), Sennacherib (B.C. 705–681), and Esarhaddon (B.C. 681–668) lie under the hill called Nabi Yûnis, and those of the palaces and other buildings of Ashur-bani-pal (B.C. 681–626) under the mound which is known locally as "Tall al-'Armûshîyah," i.e., "The Hill of 'Armûsh," and "Kuyûnjik." The latter name is said to be derived from two Turkish words meaning "many sheep," in allusion to the large flocks of sheep that find their pasture on and about the mound in the early spring. These two great mounds lie close to the remains of the great west wall of Nineveh, which in the time of the last Assyrian Empire was washed by the waters of the river Tigris. At some unknown period the course of the river changed, and it is now more than a mile distant from the city wall. The river Khausur, or Khoser, divides the area of Nineveh into two parts, and passing close to the southern end of Kuyûnjik empties itself into the Tigris. The ruins of the wails of Nineveh show that the east wall was 16,000 feet long, the north wall 7,000 feet long, the west wall 13,600 feet, and the south wall 3,000 feet; its circuit was about 13,200 yards or 7½ miles.
Discovery of the Library of the Temple of Nebo at Nineveh.
In the spring of 1852 Layard, assisted by H. Rassam, continued the excavation of the "South West Palace" at Kuyûnjik. In one part of the building he found two small chambers, opening into each other, which he called the "chamber of records," or "the house of the rolls." He gave them this name because "to the height of a foot or more from the floor they were entirely filled" with inscribed baked clay tablets and fragments of tablets. Some tablets were complete, but by far the larger number of them had been broken up into many fragments, probably by the falling in of the roof and upper parts of the walls of the buildings when the city was pillaged and set on fire by the Medes and Babylonians. The tablets that were kept in these chambers numbered many thousands. Besides those that were found in them by Layard, large numbers have been dug out all along the corridor which passed the chambers and led to the river, and a considerable number were kicked on to the river front by the feet of the terrified fugitives from the palace when it was set on fire. The tablets found by Layard were of different sizes; the largest were rectangular, flat on one side and convex on the other, and measured about 9 ins. by 6½ ins., and the smallest were about an inch square. The importance of this "find" was not sufficiently recognized at the time, for the tablets, which were thought to be decorated pottery, were thrown into baskets and sent down the river loose on rafts to Basrah, whence they were despatched to England on a British man o' war. During their transport from Nineveh to England they suffered more damage from want of packing than they had suffered from the wrath of the Medes. Among the complete tablets that were found in the two chambers several had colophons inscribed or scratched upon them, and when these were deciphered by Rawlinson, Hincks and Oppert a few years later, it became evident that they had formed part of the library of the Temple of Nebo at Nineveh.
Nebo and His Library at Nineveh.
Nothing is known of the early history of the Library1 of the Temple of Nebo at Nineveh. There is little doubt that it was in existence in the reign of Sargon II, and it was probably founded at the instance of the priests of Nebo who were settled at Nimrûd (the Calah of Gen. X, 11), about 20 miles downstream of Nineveh. Authorities differ in their estimate of the attributes that were assigned to Nebo (Nabu) in Pre-Babylonian times, and cannot decide whether he was a water-god, or a fire-god, or a corn-god, but he was undoubtedly associated with Marduk, either as his son or as a fellow-god. It is certain that as early as B.C. 2000 he was regarded as one of the "Great Gods" of Babylonia, and about 1,200 years later his cult was general in Assyria. He had a temple at Nimrûd in the ninth century B.C., and King Adad-Nirari (B.C. 811–783) set up six statues in it to the honour of the god; two of these statues are now in the British Museum. Under the last Assyrian Empire he was believed to possess the wisdom of all the gods, and to be the "All-wise" and "All-knowing." He was the inventor of all the arts and sciences, and the source of inspiration in wise and learned men, and he was the divine scribe and past master of all the mysteries connected with literature and the art of writing (, duppu sharrute). Ashur-bani-pal addresses him as "Nebo, the beneficent son, the director of the hosts of heaven and of earth, holder of the tablet of knowledge, bearer of the writing-reed of destiny, lengthener of days, vivifier of the dead, stablisher of light for the men who are troubled" (see tablet R.M. 132) In the reign of Sargon II the temple library of Nebo was probably housed in some building at or near Nabi Yûnis, or, as George Smith thought, near Kuyûnjik, or at Kuyûnjik itself. As Layard found the remains of Nebo's Library in the South West Palace, it is probable that Ashur-bani-pal built a new temple to Nebo there and had the library transferred to it. Nebo's temple at Nineveh bore the same name as his very ancient temple at Borsippa (the modern Birs-i-Nimrûd), viz., "E-Zida."
See also: Senaquerib, Babylon, Babilonia
 “From that land he went to Assyria an built Nineveh, Rehoboth-Ir, Calah, and Resen between Nineveh and Calah (that is the principal city).”
 The Babylonian Story of the Deluge as Told by Assyrian Tablets from Nineveh, by E. A. Wallis Budge.