Among the many handsome old houses on Arbor Hill’s Ten Broeck Avenue is one tall brownstone that is the site of a very unusual haunting, the Ten Broeck Mansion.. The ghost that walks its uppermost floors seems to have no connection to the building itself. A gentleman named George Dawson built the house, with a door flanked by white columns, in 1859. In the mid-20th century, though, children who lived in the house reported seeing a strange man whenever they ventured to the top floor. The mysterious and solemn figure, which often appeared in otherwise empty hallways, gave no hints as to his identity or why he haunted this once-elegant house. But he wore the clothing of a 17th-century Dutch soldier, complete with a metal helmet similar to those currently on display in the New York State Museum. Perhaps this man met his end or was buried on the steep hill where the house stands in the 1600s (at the time, the only permanent Dutch settlement nearby was Fort Orange nearly a mile and a half to the south) and continued to haunt the site itself, even after the brownstone was built centuries later.