From a drive along the Delaware coast in November...

This is one of eleven remaining reinforced concrete towers built in 1941 to protect the Delaware Bay from enemy attack.
Trying to find credible notes on these towers to have "interesting info" to add here shows how the internet offers a wide variety of "facts" --- is the tallest tower 81 feet high, or is it 94 feet? Or 120 as one site claims?
Were they intended strictly to sight enemy ships as one website insists, or were they built for firing upon the enemy, as multiple sites state?
Did they ever see action? One site says a German ship was indeed sunk off the Delaware coast; others say nothing of the sort.
Looks like there'll have to be a trip to the restored tower and visitor center at Cape Henlopen State Park one weekend this spring to learn more!