Robert Warren junior took over the running of the Warren Estate after the death of his father in 1869. It was he who successfully managed to resolve the outstanding debt issues on the estate. He had been living directly across the road from Killiney Castle in Wyvern since 1860, when it was built. It appears that by selling off parts of the estate he managed to retain ownership of Killiney Park, Vico Fields and Wyvern. In 1887 he finally sold the main estate for £5,000 to allow for the creation of the public amenity we now know as Killiney Hill Park. It was not until 1889 that agreement was eventually reached with the owners, including Warren, which allowed for the opening of the Vico Road to the public. He remained in Wyvern until his death in 1894.