I am always amazed how much interest and attention is given to the Dutch Gardens. Built in 1902 poorly and improperly that they had to be rebuilt by 1911. Not much Dutch about it but was built during the Colonial revival period of interest ca 1900-1920s as the 150 anniversary of America Independence approached. By the early 60s the gardens were in decay once again with the west side taken for the 2 pools which again poorly planned and built soon ran into problems. Again a lot of money wasted by another poorly designed and planned Parks Dept project .
Regarding the hill south of the VC Mansion. My thought is that it is not man made or built by slaves or others. The 1781 map indicates a 3 sided deep ridge much as a present day topgraphical map would indicate the same today, steep hillside slopes.. The last glacier created the parade ground by wearing down the Inwood Marble while leaving the Riverdale ridge to the West and Van Cortlandt ridge to the East made of Fordham gneiss.
This ridge is basically the end of the parade ground that was likely eroded by the glaciers movement south and the receding waters, and cut deeper by the water action from Tibbett’s Brook over the centuries. The ‘U” shape and course of the brook is likely due to nature as well. Major storms can and do change the shape of streams, creeks and rivers and in a few cases have changed the directional flow of rivers.
Today the area is reverting back to a more natural state until someone in Parks or Community Board comes up with another poorly designed project to waste taxpayers money.