Fort Carroll Light is a derelict lighthouse consisting of a short wooden tower on the walls of its namesake fortifications in the Patapsco River.

The Spanish–American War prompted a project to upgrade the fort's guns to (then) modern naval weapons, and this displaced the light to a new location on the northwest corner.

The federal government retained the property, however, and the coast guard used it for a pistol range and for temporary quarters for seamen whose ships were being fumigated.

Various schemes for reuse ensued, and eventually in 1958 the property was sold to Benjamin Eisenberg, a Baltimore lawyer who intended to build a casino there.

Jurisdictional issues nixed this, and the property has never been put to commercial use, though at one point a large number of peach trees were planted.