The two cannons at the foot of the water tower are thought to be from either the harbor defenses of Santiago, Cuba or San Juan Hill. In any event, they honor the US Army's 6th Infantry Regiment, and that unit's service in the Spanish-American War. They're 24 pound cannons and are engraved with the Royal Cypher of Charles III of Spain.
The north cannon is engraved "Barcelona, 22 De Juliode 1769 (July 22, n1769), and the south canon says "Barcelona, 22 De Juniode 1768 (June 1, 1768).
In addition, the left gun is inscribed "EL BELISARIO," who was a Byzantine general, A.D. 505-565, and "No. 82 CORBE Y ESTANO DE AMERICA ALIC DO CON LATON," (Copper and tin of American made into brass").