The scale of the original excavation defies modern intuition. Records show Norwich Cathedral alone consuming about 320,000 tonnes of peat per year - hauled by boat down the Bure and the Yare from the marshlands. Multiply that by every great hall, monastery, town and cottage hearth in East Anglia, and the workforce required becomes staggering. For two or three centuries, thousands of men dug peat by hand from the marshes, stacking and drying turves on the banks before shipping them out as fuel. They left behind a landscape of rectangular pits separated by narrow walkways. When the climate shifted and the seas rose in the late thirteenth and fourteenth centuries, the pits filled with water, the walkways drowned, and the pits coalesced into the broads we know today.

Today the Broads cover 303 square kilometres - most of it in Norfolk, some spilling into Suffolk - with over 200 kilometres of navigable waterway. Seven rivers connect the system: the Bure, the Yare, the Waveney and their tributaries. Most of the broads are less than four metres deep. Thirteen are routinely open to boats; another three have navigable channels. In summer the rivers fill with hire cruisers from Wroxham and Horning, sailing dinghies on the bigger broads, kayaks slipping between reedbeds. The Broads Authority oversees it all, juggling three duties that often pull in different directions: conserve the landscape, encourage public enjoyment, and protect the interests of navigation.

In 2015 the Broads Authority approved a marketing rebrand to 'The Broads National Park.' The label is true and not quite true at once. The Broads do receive a national park grant. The Authority shares the conservation and public-enjoyment duties of the English National Parks. But the Broads were never officially designated a National Park under the legislation that created the Peak District, the Lakes, and Snowdonia. They have their own act - the Norfolk and Suffolk Broads Act 1988 - because navigation, the third statutory duty, has no equivalent in the upland parks. Some locals chafe at the new branding; others welcome the recognition. The signage now reads 'National Park.' The legal text still reads 'special statutory authority.'

The conservation designations stack thick across the Broads. Twenty-eight Sites of Special Scientific Interest combine into the Broadland Special Protection Area for birds. Several stretches are National Nature Reserves: Bure Marshes, Hickling Broad, Martham Broad, Mid-Yare. The reedbeds support the largest UK populations of bittern - the elusive, booming heron whose mating call carries across reed in spring. Marsh harriers cruise the marshes; swallowtail butterflies, Britain's largest, are found nowhere else in the UK. Norfolk reed cut from the broads still thatches roofs across England. The wetland was nearly destroyed by twentieth-century nutrient pollution; decades of work to reduce phosphate inputs have slowly returned clarity to the water.

The Broads invented the British inland boating holiday. The black-sailed Norfolk wherries, flat-bottomed cargo boats that hauled grain and peat through the nineteenth century, were retrofitted in the 1880s for tourists by John Loynes of Wroxham. By Edwardian times, families were cruising from broad to broad in hired wherries with cabins and crew. Today the wherries are mostly preserved as heritage vessels, but the holiday tradition continues with thousands of hire cruisers based out of Wroxham, Horning, Stalham, and Brundall. Add the writers - Arthur Ransome set Coot Club and The Big Six on these waters - and the cultural footprint extends well beyond the small geographic one.