Millions of people lined the streets of London on the day of Princess Diana's funeral. The original plan was for Diana to be buried at the Spencer Family vault, but her brother, Earl Charles Spencer, changed his mind because he wanted Prince William and Prince Harry to be free to visit her grave whenever they wished without being concerned about privacy.
Spencer believed it was best for Diana to be buried at the family home, Althorp House, to ensure her loved ones always had unrestricted access. They buried her in an ornamental lake known as The Oval, which is ‌within Althorp Park's Pleasure Garden, where there is an arboretum where Diana and her loved ones, including her sons, all planted trees.
Spencer chose the remote spot to ensure that trespassers couldn't possibly vandalize or stalk the burial because he was worried about the people who had conspiracy-type ideas about Diana. In 2017, there were four attempted break-ins, with Spencer saying, "There are some odd people out there and keeping her right here is the safest place."
Spencer provided some of the reasoning for the specific location in 1998, stating that he believed the water would "act as a buffer against the interventions of the insane and ghoulish, the thick mud presenting a further line of defense." He added that they "all agreed that, with its beauty and tranquility, this was the place for Diana to be."