I recently visited Northerly Island on a beautiful spring day. All along the eastern side of the island are rocks and stones, somewhat like what you'll find all along the Lake Michigan shoreline in Chicago, but it seemed like there were more intact pavers and recognizable bricks and stones from houses than there are in other places, including pieces of bathroom floor tile still stuck to concrete.

At any rate, almost directly east across the island from the old terminal, the shoreline takes a 90-degree turn eastbound for about 75 yards. About 10 yards after it turns, there is a stone structure built a few feet above the waterline, with a doorway facing the lake. Upon first glance, it looked to be a relic - perhaps some pre-airport caretaker's house or pump house or something. However, the more I looked at it, the more it seemed like someone had built this house more recently, Inca-like, without mortar, out of the limestone slabs that are scattered along the shoreline. I am not totally sure. I It was tough to get close to it, but it looked as if there may have been a door in the doorway. Not sure.

Does anyone know anything about this structure, when it was built, who built it, and what it was for?