The Ninety Mile Beach is a sandy stretch of south-eastern coastline of Victoria, Australia along the Gippsland Lakes region of East Gippsland on Bass Strait. The beach is just over 151 kilometres (94 mi) long running north-eastward from a spit near Port Albert to the man-made channel at Lakes Entrance. The beach is located just over 250 kilometres (160 mi) from Melbourne and can be reached from the South Gippsland Highway passing the coastal towns of Woodside, Seaspray, Golden Beach, and Loch Sport.

The beach is made up of long sandy dunes which separate the various lakes and lagoons from the ocean. For the northern part of its route the beach runs along a sandbar on what amounts to a series of tidal islands and behind which are several large lakes and numerous shallow littoral lagoons. The three main lakes are Lake King, Lake Victoria and Lake Wellington. The area comprises The Lakes National Park. [Source]

The comments on the original post and a search on Tineye did not identify the source of the picture. Similar, but not identical photos were spotted in a Google Image search that sourced Tourism Victoria, but I was unable to find an exact match. Please let us know in the comments if you know who the photographer is.