Metropolitan Transportation AuthorityThe top of an old wall was discovered by workers digging a new subway tunnel under Battery Park. Three weeks after the Metropolitan Transportation Authority started digging a subway tunnel under Battery Park, the project hit a wall. A really old wall. Possibly the oldest wall still standing in Manhattan. It was a 45-foot-long section of a stone wall that archaeologists believe is a remnant of the original battery that protected the Colonial settlement at the southern tip of the island. Depending on which archaeologist you ask, it was built in the 1760's or as long ago...