Fort Desoto Park, FL
29,000 lbs. of Mortar had a way of saying 'don't misbehave' to shipping vessels back at the turn of the century...
These mortars controlled the main shipping lane into Tampa bay. A ship entering the bay had to pass between Fort Dade, on Egmont Key, and Fort De Soto. For that entire time, they were directly under the guns of the batteries on either side of them.
Fort De Soto has the only four 12-inch seacoast rifled mortars (model 1890 mounted on 1896 carriages) in the continental United States.