Royalty

Likely just looking to disrupt any party times by having the place shut down when they found them further down the line. Although, that would require no one knowing you'd thrown them over in the first place. We did a day with the sniffer dogs in the grounds there and the handlers said people would chuck stuff like that over to either collect at a later date when they were in or to cause disruption when it was found later. Imagine a garden party being cancelled because they'd found a suspicious package in the bushes during a morning search or something.