
Old Coastguard Station in Robin Hood's Bay and a second site in Ravenscar are considered "no longer viable in the long term" by the charity, despite efforts to improve their performance.
According to the National Trust, both sites will cease trading and close to customers on 6 September.
The decision has resulted in a "number of roles" being made redundant, which followed a period of consultation with staff.
A National Trust spokesperson said: "Like many hospitality businesses, we have faced significant challenges in recent years.
"Despite efforts to improve performance, these cafés are no longer viable in the long term.
"As a charity, we have a responsibility to use our resources effectively so we can continue to deliver our conservation work."

Andy Hill, from Cloughton, often visits the Ravenscar visitor centre with his wife and said he was "disappointed" by the news of its closure.
"We've seen it packed out by families, older people who want a coffee and a look at the view, it's really nice," the 75-year-old said.
"A lot of people stop there because it's halfway between Scarborough and Whitby.
"It's just a big shock. There will be nobody to give advice on how to get down the coast safely or how to see a seal colony."
The National Trust spokesperson added: "We know this news will be disappointing for staff, local communities and visitors.
"We remain committed to helping people enjoy the Yorkshire coast and will work with colleagues, communities and stakeholders to explore future opportunities for these buildings and how they can best support our ambitions for the North Yorkshire coast."
They thanked staff for their dedication and professionalism at the venues over many years.
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