Prospectors in Moliagul, Australia, discovered the largest alluvial gold nugget ever found, known as the Welcome Stranger.

Moliagul is a locality in the Shire of Central Goldfields and Shire of Loddon, Victoria, Australia, located 202 kilometres (126 mi) northwest of Melbourne and 60 kilometres (37 mi) west of Bendigo. The area is notable for the discovery of a number of gold nuggets. These finds include the world's largest, the Welcome Stranger, which was discovered in 1869 by John Deason and Richard Oates. At the 2021 census, Moliagul had a population of 80.

Alluvium is loose clay, silt, sand, or gravel that has been deposited by running water in a stream bed, on a floodplain, in an alluvial fan or beach, or in similar settings. Alluvium is also sometimes called alluvial deposit. Alluvium is typically geologically young and is not consolidated into solid rock. Sediments deposited underwater, in seas, estuaries, lakes, or ponds, are not described as alluvium. Floodplain alluvium can be highly fertile, and supported some of the earliest human civilizations.

A gold nugget is a naturally occurring piece of native gold. Watercourses often concentrate nuggets and finer gold in placers. Nuggets are recovered by placer mining, but they are also found in residual deposits where the gold-bearing veins or lodes are weathered. Nuggets are also found in the tailings piles of previous mining operations, especially those left by gold mining dredges.

Welcome Stranger is the name of the largest alluvial gold nugget ever discovered. It was unearthed by Cornish miners John Deason and Richard Oates on 5 February 1869 in Moliagul, 9 miles north-west of Dunolly in Victoria, Australia.