The fine print:
Your free visit can only be redeemed during April 1st – May 31st 2014 and you must present your stamped receipt (for paid admission dated from April 1st – April 30, 2014) in order to be eligible for free entry. Up to the same value of individual admissions will be eligible for free entry as per the original receipt and this offer can only be redeemed once. This offer cannot be combined with any other offer. No cash value.
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