The London Ecology Unit (LEU) provided advice to London boroughs on nature conservation issues between 1986 and 2000. It published a series of handbooks, some on specific conservation issues, and some which gave detailed descriptions of Sites of Importance for Nature Conservation (SINCs) in each borough. The handbooks provided a basis for addressing nature conservation in the boroughs' Unitary Development Plans, and for policy decisions in planning and leisure services.[1]