FYI since early 2021 the NT have changed access across the WImpole Estate. If going from East to West, they have made it completely unobvious that you are allowed to cycle across the Estate. They want you to park in their shiny new carpark and charge you £16 for the privilege of cycling across a public access route (speaking to a volunteer on the door won't help, they lied to me as I tried to avoid cycling along a busy 50mph road) . You need to ignore all car parking signs, and go to the old access road (which is signed for deliveries and has an unfriendly security guard sign). There is a double side gate for pedestrians / bikes. Access from West to East isn't so cryptic.