English: Martham Broad - the viewpoint. A narrow track leads from the public footpath down to the water's edge, allowing a good view across. A boathouse can be seen in the distance (to the right of the tree seen in foreground). The tiny black dots on the surface are created by a variety of ducks which are wintering here > 1107369. Martham Broad National Nature Reserve forms part of the Upper Thurne Broads and Marshes SSSI and is owned and managed by Norfolk Wildlife Trust. The reserve consists of open shallow brackish water surrounded by reeds and sedge fens and is believed to have been created by the flooding of peat bogs prior to the 13th century. Due to its excellent water quality, the broad has one of the most diverse assemblages of aquatic plants in Broadland. The surrounding reed swamp is composed of common reed and commercial sedge beds.