A community group's plan to take over Kinloch Castle on Rum has been knocked back by the public body that owns the 19th Century property.
Kinloch Castle Friends Association (KCFA) proposed developing part of the castle into a 51-bed B&B and later turning other areas into a museum.
But Scottish Natural Heritage (SNH) has rejected a request to transfer the property to KCFA as a community asset.
SNH has concerns the group does not have funds to maintain the castle.
A spokeswoman for KCFA said the group will appeal the decision and continue to work towards taking over and preserving the property and its contents.
In its decision, SNH also said there was a risk KCFA's business case could fail.
SNH said KCFA carried out a range of important work and recognised its members would be disappointed by the decision.
The public body added that it hoped discussions could continue with KCFA about the future of the site.
Nick Halfhide, SNH's director of sustainable growth, said: "Having carefully considered all the evidence presented, we concluded that the merits of the request fell short of the necessary requirements for a successful asset transfer application.
"We ensured that the assessment process was not only thorough and fair, but also transparent and the full decision and papers will be made available on our website."
Rum is in the Small Isles south of Skye.
Kinloch Castle was built in 1897 as a hunting lodge for Lancastrian industrialist George Bullough and he had it luxuriously furnished.
The property fell into decline after World War I and was taken over by SNH's predecessor, the Nature Conservancy, in 1957.
It has required extensive restoration work over the years.