SAN ANTONIO, Texas - Archaeologists at the Alamo have unearthed a second intact battle-era cannonball in less than three months, officials announced.

What we know: The latest artifact, a solid iron cannonball, was discovered June 2 outside the northeast corner of the historic Alamo Church.

It was found in an excavation unit adjacent to where researchers uncovered a solid bronze cannonball on March 5-one day before the 190th anniversary of the historic 1836 battle.