Webthe casque in milwaukee isn't buried at city hall, and the one in new york isn't buried at the statue of liberty or ellis island. Start with the famous places referenced in the. Webpublished in 1982, the secret features illustrations and poems that offer clues to 12 hidden treasures—ceramic “casques” with an enclosed key—buried in cities. June 1, 2016, 12:00am. Lake park, milwaukee, where many believe one of the.