Harry Potter in Oxford Walking Tour for Two - Key InfoVoucher Validation Your voucher is valid until 01 Jul 20 You must validate book and use your voucher within the voucher expiry date.Duration: This experience will last approximately 1 1/2 hours.Group Size: This experience is for two people there will be other people there on the day.Weather Dependent: NoSpectators: Unfortunately this experience is not suitable for spectators.There is no minimum age for this experience under 16s must be accompanied by an adult.Availability: This experience is available on selected dates throughout the year.