Under the ivy is a wall of double brick construction with cavities for overwintering butterflies and moths and their pupae (Brimstone, Peacock, Red Admiral, Orange and Red Underwing). This was designed built as part of the development of this part of the Park as a butterfly sanctuary. In 1994 it was designated as Britain's first urban butterfly sanctuary. The Park includes micro habitats specifically designed for butterflies, such as south facing enclosed glades with shelter from the wind, and the curved brick wall before us.