A museums expert has expressed concern over whether Nottinghamshire can support two major new Robin Hood attractions.
A county council-backed private venture will see a medieval-style castle and themed attractions built near the heart of Sherwood Forest.
The city council is moving forward with plans to revamp the city castle site.
Neville Stankley, from Nottingham Trent University, said they must co-operate or could face a struggle for visitors.
Discovery Attractions, whose senior management have experience with Madame Tussauds and Warwick Castle, has unveiled plans for a £13m attraction near Edwinstowe.
As well as the castle, the site will have a new forest visitor centre, interactive film shows and jousting area.
The city council's plans include a new castle visitor centre, with better access to nearby caves and upgraded museum galleries.
Its plans are at an earlier stage but officials have said they are considering seeking up to £30m of funding.
Mr Stankley, from the Centre for Museum and Heritage Management at the university, said while the area needed a major Robin Hood attraction, he had concerns about the proposals.
"I just hope they are sustainable," he said. "In the back of my mind I worry for the long-term future of them.
"If they are set up correctly and they can create a virtuous circle of interest then the potential is that they could both work.
"But the immediate question for the Sherwood Forest centre is how does it sustain itself out of the summer - in the summer it will have lots of interest and numbers but how to sustain that through the winter?"
Ted Cantle, who chairs the group working on Nottingham Castle, said: "These schemes will be complementary because Sherwood Forest will be much more 'Legend of Robin Hood' but our scheme in the castle, while bringing in Robin Hood, is going to be a much more serious, historical exposition."