Located on the north coast of the county of Norfolk, between the villages of Titchwell and Thornham, about 8 km (5.0 mi) east of the seaside resort of Hunstanton, its 171 hectares (420 acres) include reed beds, saltmarshes, a freshwater lagoon and sandy beach, with a small woodland area near the car park.

The reserve is important for some scarce breeding birds, such as pied avocets on the islands, and western marsh harriers, Eurasian bitterns and bearded reedlings in the reeds.

Titchwell Marsh is archaeologically significant, with artefacts dating back to the Upper Paleolithic, and has remains of military constructions from both world wars.

The archaeological record is poor until about 20,000 years ago, partly due to the prevailing conditions, but also because the coastline was much further north than at present, so that many sites are now under the sea.

[1] Early Mesolithic flint tools with characteristic blades up to 15 cm (5.9 in)[2] long found on the present-day coast at Titchwell date from a time when it was 60–70 km (37–43 mi) from the sea.

[6] Medieval and later pottery has been found at Titchwell, and the peat and silts which overlay the sediments deposited by the retreating glaciers have signs of post-medieval ploughing.

[5] The draining of Norfolk's coastal marshes commenced in the late 17th and 18th centuries, and sea defences including the "Old Lord's Bank" at Titchwell were shown in maps from 1786 and 1797.

[5] Between 1942 and 1945, the marsh was used by the Royal Tank Regiment;[10] an armoured fighting vehicle gunnery range was established and new banks were constructed for firing practice, with targets set at 900 m (980 yd) intervals.

Bombing practice was supervised from a control tower, which was demolished in 1962, leaving only a concrete structure opposite the end of Titchwell's west bank.

[16] The construction of a new sea wall across the reserve created a shallow freshwater lagoon, with a reed bed on its northern side and a vegetation-free brackish marsh.

12 hectares (30 acres) of land to the east of the reserve was bought in 1993; much of this was formerly part of the firing range, and large amounts of barbed wire caused problems when the area was being converted to reed bed and wet grazing meadow.

The main footpath continues north past the reedbed to the freshwater lagoon and the Island Hide, then reaches a bank running across the reserve.

The footpath continues past a tidal lagoon, and over another bank to a saltmarsh, formerly ending at a raised wooden seawatching platform on the dunes by the beach.

[27] The key breeding species are reed bed specialists such as the marsh harrier, Eurasian bittern and bearded reedling, together with the avocet, the RSPB's symbolic bird.

[30] These problems were addressed by managing water levels and excavating some of the reed bed to create open, reed-fringed pools, and stocking the lagoon with the common rudd; breeding recommenced in 2004.

[31] Other breeding birds include ringed plovers and Eurasian oystercatchers in the sand dunes, and water rails in the reed bed.

[32] In the autumn, species arrive from the north, some, such as black-tailed godwits, curlew sandpipers and little stints just passing through, pausing for a few days to refuel, others staying for the winter.

Brent geese feed on sea lettuce and other green algae,[36] and hundreds of European golden plovers may roost on the reserve at high tide.

[32] In the evenings, large flocks of pink-footed geese fly over Titchwell on their way to roost, and barn owls and hen harriers quarter the marshes.

[39] Major rarities in recent years include a Pacific golden plover and a great knot in 2016,[40] and a slender-billed gull and a penduline tit in 2014.

[41] Water voles are an endangered species in the UK, with a huge decline in numbers, mainly due to predation by the introduced American mink.

[47] The tiny village of Titchwell has two three-star hotels and a shop selling telescopes and binoculars, although it does not have a general store or a public house.

[48][49][50] A 2005 survey at Titchwell and five other North Norfolk coastal sites found that 39 per cent of visitors gave birdwatching as the main purpose of their visit.