The zoo owns the land behind the new enclosure as far as the Shropshire Union canal, more than 200m to the north. Obviously that land could be developed as a new part of the zoo one day, but the current plans involve the south side of the zoo.
@JoeDK14 Le Parc Des Felins in France. They have four different and massive lion enclosures (two or three acres each). I am making no affirmation or denial of the validity of lion subspecies by listing these four "types"; I am just stating what the park signage says.
Asiatic lion
Angolan lion
East African lion
White South African lion