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The city reaches south-east through Dandenong to the growth corridor of Pakenham towards West Gippsland, and southward through the Dandenong Creek valley, the Mornington Peninsula and the city of Frankston taking in the peaks of Olivers Hill, Mount Martha and Arthurs Seat, extending along the shores of Port Phillip as a single conurbation to reach the exclusive suburb of Portsea and Point Nepean. In the west, it extends along the Maribyrnong River and its tributaries north towards Sunbury and the foothills of the Macedon Ranges, and along the flat volcanic plain country towards Melton in the west, Werribee at the foothills of the You Yangs granite ridge south west of the CBD. The Little River, and the township of the same name, marks the border between Melbourne and neighbouring Geelong city.

Little River marks the boundary between Melbourne and which city?
Geelong