Lucan-Ilderton Boundary Lines – Start at Hwy #4 and Whalen Line. South on Highway #4 to County Road 20 (Denfield Road). Continue South on County Road 20 to Hwy #7. West on Hwy #7 to Hwy #81. South on Hwy #81 to Hwy #22, east on Hwy #22 to the London city limits. North and east along the city limits to County Rd #23 (Highbury). North on #23 to Hwy #7, east on Hwy #7 to Whalen Line. Northwest on Whalen Line to Hwy #4.