Former Michelin starred restaurant, the Walnut Tree Inn, near Abergavenny, has closed for business.
In a statement on its website the current owners said they had been forced to close the restaurant "pending some reorganisation".
The Walnut Tree Inn, which is has been credited with putting Wales on the culinary map, was founded by Franco and Ann Taruschio, but has since changed hands.
In 2001 it was taken over by new owners Francesco Mattioli and his then business partner and Michelin-starred chef, Stephen Terry.
The statement on the restaurant's website added: "We apologise to our customers for having to close at short notice. Please watch this website for the reopening date and an even better restaurant."
TV chef Gordon Ramsay featured The Walnut Tree in his Kitchen Nightmares series in 2004, clashing with Mattioli over its menu and prices.
Mattioli later said he was unhappy with the portrayal of his business.
By Kerstin Kühn
E-mail your comments to Kerstin Kühn here.