A park's last remaining Japanese building has been closed "for public safety reasons".
The fishing hut at Guernsey's Saumarez Park needs repairs to its platform and roof.
A Japanese house and temple used to sit nearby but became dilapidated during World War Two.
They were brought to the island by Baron James de Saumarez, the grandson of Admiral Lord James de Saumarez - a contemporary of Admiral Lord Nelson.
Vandalism contributed to them later being removed from the park.
The de Saumarez family's private estate was acquired by the States after the death of the younger James in 1937 and remains the largest public park in Guernsey.
Tour guide Eric Grimsley said it was unlikely the decorative hut was used for fishing - although carp remain in the pond.
He said the younger James became fascinated by the Japanese culture after a visit: "He brought back so many bits of furniture and objects from Japan.
"Within the park we've got bamboos - they came from Japan, originally there were 30 different types of bamboo.
"He also brought back 35 different types of camellia... some of them are just coming out to bloom now."
A Guernsey States spokeswoman said the fishing hut was "recognised as being greatly valued by the community".
She said the cost of repairs was being investigated and added a funding bid to pay for the work would be made, which would be considered alongside other bids for "minor capital" spending on States' properties.
"The structure is in poor condition and whilst there is no immediate concern that it will collapse, people are advised not to enter it."