Portsea Backbeach is on the ocean side of Mornington Peninsula, around 1500 metres behind the bayside Portsea Beach. This area is wild coastline, known for treacherous sea conditions that have taken lives, including that of Prime Minister Harold Holt in 1967.
The beach is a long straight strip of sand which travels 800m north-east to the rock feature London Bridge on one side and around 2 km south-west to Sorrento Backbeach on the other.
The area is popular with walkers, sunbathers and experienced surfers. Surf Fishing is also popular along the shore.