At Lachish, archaeologists have discovered the largest gate complex in Israel. The massive double gate included both an outer gate structure and an inner gate. Its large size testifies to the strength and importance of ancient Lachish.

The Lachish Letters
Mr. J. L. Starkey and his worthy associates directed the excavations at Lachish from 1932 to January 10, 1938, and made many significant discoveries, the most important being twenty-one letters (now known as The Lachish Letters) which they found among the ashes and charcoal in the guard room adjoining the outer gate of the city. These letters were written with carbon ink by a certain Hoshaiah (Nehemiah 12:32, Jeremiah 42:1, 43:2), a subordinate military officer stationed at an outpost near Jerusalem, to Joash the commanding officer at Lachish. These short messages were written during the last years of Jeremiah (c.588 B.C.) and reflect the troubled period through which the kingdom was passing during Zedekiah’s reign just before the fall of Lachish and some two years before the fall of Jerusalem. They were evidently written within a period of a few days or weeks, as is indicated from the similarity of the fragments, five of which fit together as pieces of one vessel.

Letter I contains a list of nine proper names, five of which are found in the Old Testament. Three appear only during the time of Jeremiah. In Letter IV

Hoshaiah writes:
And let my lord know that we are watching for the signals of Lachish according to all the indications which my lord hath given, for we cannot see Azekah.

Jeremiah mentions “fire” signals (Jeremiah 6:1), and tells how the king of Babylon “fought against Jerusalem, and against all the cities of Judah that were left, against Lachish, and Azekah: for these defenced cities remained of the cities of Judah” (Jeremiah 34:7). - More information on the Letters

Lachish Under Siege
Of further interest is the fact that archaeological digs at the city of Lachish bear out the details of Sennacherib’s wall relief. Extensive archaeological digs at Lachish from 1935 to 1938 by the British, and again from 1973 to 1987 under Israeli archaeologist David Ussishkin and others, have revealed a treasure trove of artifacts, each of which fits the events depicted by Sennacherib. Concerning the Assyrian siege of Lachish, William Dever noted:

"The evidence of it is all there: the enormous sloping siege ramp thrown up against the city walls south of the gate; the double line of defense walls, upslope and downslope; the iron-shod Assyrian battering rams that breached the city wall at its highest point; the massive destruction within the fallen city.... Virtually all the details of the Assyrian reliefs have been confirmed by archaeology.... Also brought to light by the excavators were the double city walls; the complex siege ramp, embedded with hundreds of iron arrowheads and stone ballistae; the counter-ramp inside the city; the destroyed gate, covered by up to 6 ft. of destruction debris; huge boulders from the city wall, burned almost to lime and fallen far down the slope."
(2001, pp. 168-169).

The Assyrian monarch’s siege of Lachish is documented by the biblical text, and the destruction of the city is corroborated by the massive carving dedicated to the event in Sennacherib’s palace at Nineveh, as well as the actual artifacts found in stratum III at Lachish

The Amarna Letters
The town of Lachish is also mentioned in the Amarna letters.
Letter from Pabi, Prince of Lachish, to Akhenaton

Scriptures
Joshua 10:31 And Joshua passed from Libnah, and all Israel with him, unto Lachish, and encamped against it, and fought against it:

2 Kings 18:14 And Hezekiah king of Judah sent to the king of Assyria to Lachish.

Isaiah 37:8 So Rabshakeh returned, and found the king of Assyria warring against Libnah: for he had heard that he was departed from Lachish.