A Bristol man proposed to his girlfriend by arranging for a diamond ring to be placed in a display cabinet beside a stuffed seagulls exhibit.
Rob Colbourn,30, also wrote his own exhibit label beneath the cabinet which read: Ring used by Rob Colbourn in the proposal of marriage to Marisa Stabler.
As they wandered around the gallery the web developer pointed out the ring to Miss Stabler, 27, and proposed to her.
But he could not get down on one knee until museum staff opened the cabinet.
Mr Colbourn, who lives with Miss Stabler in the Stoke Park area of Bristol, said he was nervous that she would not accept.
He wanted to propose on the day they celebrated 18 months together and chose an indoor venue because the weather forecast was bad.
The couple had been to the museum on dates and last year spent their first Valentine's Day at the museum's Love Exhibition.
A spokeswoman for Bristol's City Museum and Art Gallery said it was happy to help.
"The museum is a romantic building but it was unusual to be asked to do something like this," she said.
"We thought we could help make it a special occasion for them."