Not certain about the official designation and what it encompasses physically but it's a safe bet that it stretches from approximately 16th Street to 23rd Street. At least as far as the wonderfully sculpted garden, depth of view etc.
It runs roughly from the Con Ed power plant on the East River to 23rd Street.
There is no when, it has been...opened...for many years. Physically it starts at 14 and goes to 23 street
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