Hockham Mere is the site of a former lake, >400 metres diameter, in Norfolk, England. Its biogenic sediments contain a late-Devensian & Holocene pollen record. The lake was 1.2 miles (1.9 km) west of Great Hockham in Breckland. It formed over 10,000 years ago, probably by dissolution and collapse of the underlying chalk bedrock. Worked flint tools discovered on the fringes of the former lake suggest that it was an area of significant Mesolithic occupation. In Tudor times it was a large lake, and was drained over the next two centuries. It had dried up by the middle of the 18th century. It is now an area of swampy land and carr woodland, known as Cranberry Rough.