The Elizabeth Islands Military Reservation was built on land acquired by the US government in 1943.

It consisted of an early radar, an observation post, fire control towers, and artillery batteries.

These were mirrored across the channel by a single 90 mm AMTB battery at the Barneys Joy Point Military Reservation.

[1] The site today consists of the foundations of the various buildings and gun blocks.

Two fire control towers also remain standing.