After some trouble with the Disosways, Daniel Tourneur's widow, Jacqueline, and her son, Daniel Tourneur, Jr., rented out their property in New Harlem and moved to Montagne's Flat, where Daniel also owned land he inherited from his father. Following is a photograph of the area, taken in or before 1903 and published in "New Harlem past and present" in 1903, which states the following:
This illustration shows the upper boundary of Montagne's Flat, - 123d Street, looking toward the Hudson River. In the distance is Grant's Tomb, just below the northern end of the Harlem line, which crosses 123rd Street at an angle marked by the first apartment house on the left. Next on the left stands the ruins of one of Washington's old block-houses, erected during the Revolution, while to the south stretch away the beautiful woods and lawns of Montagne's Flat, now Morningside Park.
This interactive Google Map places you in the same approximate location this photo was taken. On the left is Morningside Park, formerly Montagne's Flat, as shown in the photo. Click or drag on the map to look around! (If you have a problem viewing it, use this alternate link).
Source:
New Harlem past and present; the story of an amazing civic wrong, now at last to be righted, by Carl H. Pierce, W.P. Toler, and H.D. Nutting, 1903.