(a hundred), The tower of, one of the towers of the wall of Jerusalem when rebuilt by Nehemiah, (Nehemiah 3:1; 12:39) appears to have been situated somewhere at the northeast part of the city, outside of the walls of Zion.
a hundred cubits ...
Hitchcock's Bible Names Dictionary
An hundred, a tower in Jersalem on the east wall (Neh. 3:1) in the time of Nehemiah. ...
Easton's Bible Dictionary