Otters have been spotted during the day at Strumpshaw Fen
Otters came close to extinction in Norfolk 30 years ago, but the county's otter population has recently seen an increase.
People in the RSPB's team at Strumpshaw Fen, near Brundall, are some of those who have had a rare glimpse of the elusive mammal.
The fen, in the Yare Valley, is home to many animals and birds including marsh harriers and bitterns.
But it's the otter's return which is giving real cause for excitement.
BBC Radio Norfolk's Edd Smith went along to Strumpshaw Fen at dawn to witness his first otter in the wild, joined in the hide by the RSPB's site manager Tim Strudwick.
"I must admit I'm not exactly Norfolk's answer to David Bellamy but the thought of seeing an otter in Norfolk sparked off the naturalist in me," said Edd.
"Before arriving at the fen I was aware of how fortunate I would be to see one of Norfolk's rarest mammals.
"As I walked to the RSPB's reception I caught sight of a rather excited Tim Strudwick as he beckoned me over to the water's edge.
"And there is was: a silhouette bobbing up and down, breaking through the water's surface as it passed the reed beds - my first sighting of a wild otter."
Although the otter is mainly nocturnal, otters are now frequently being spotted during the day at the fen.
"Just 10 years ago they were a kind of mythical creature here but now you've got a reasonable chance of seeing otters if you come here, even in the middle of the day," said Tim.
It wasn't always so easy to spot otters in Norfolk, with the decline starting in the 1960s.
Tim said: "There were a lot of toxic chemicals used in agriculture which got into the food chain and passed onto eels, which are a prized food of otters.
"The chemicals then built up in the otters and poisoned them."
Improvements in river water quality and the banning of certain toxic chemicals has helped to encourage the otters to return.
With more than 60 miles of waterways at Strumpshaw Fen, the otters are making great use of their environment.
"By following the otters' tracks we've realised they're using every single pool and ditch on the site which shows it's a rich environment and the otters are thriving," said Tim.
For Edd the excitement didn't stop there as the otter moved closer to the hide.
"I couldn't believe my eyes as the otter dipped under the water only to glide past the hide as it dived into the reed beds."
Otters, like most wild animals try to avoid humans but Tim is often impressed with how sociable the Strumpshaw otters are.
"To see the otter here look you in the eye and then go back to feeding - it's very comfortable with people being around and it's great to see," said Tim.