The marsh is well known for its orchids - four species grow on the marsh
A project to restore three hectares of ancient marshland at the National Trust's Hatfield Forest is complete.
Work began last November to clear the dense scrub which had covered the site.
The wildlife-rich marsh is home to 90 species of plants, as well as rare birds like reed bunting and water rail, which have been in decline in Essex.
"Members of the public couldn't see the marsh existed, as there was a band of scrub around the outside," said National Trust warden Adam Maher.
The 1000-year old marsh is made up of three areas - marsh grasslands, reedbeds and sedge beds.
The trust is going to be using a flock of 30 Wiltshire Horn sheep to keep the successive growth of hawthorn and blackthorn down.
Warden Adam Maher will be working with volunteers to maintain the site
"The sedge bed and reed bed are going to be cut on a rotation," said Mr Maher.
"They will be split into blocks of four and then cut on a four-yearly rotation and the organic growth will be removed so we are not drying up the area.
"Basically it's getting drier. So that's what we want to stop. We're losing the actual thing that makes the site very important," he added.
The marsh is home to four different types of orchid - common spotted, Southern marsh, pyramidal and early marsh orchid.
"It's very unique that there should be this many orchids growing together," said Mr Maher.
The project has reinstated a historic view towards the lake
The next stop for the marsh project is survey work.
"Starting over the summer we're carrying out surveys on birds, reptiles, moths, plants, dragonflies and other invertebrates to get the best information we can," he said.
The marsh is open all year, except when grazed by sheep.
Visitors are asked to keep to the fence line path to protect the fragile habitat.