When experts examined the body of Billy the Seal they discovered he was a she
The skeleton of one of Cardiff's most famous residents is a key attraction of a new gallery at the National Museum.
Billy the Seal, who lived in a pool in Victoria Park, is back on show for the first time in nearly 20 years.
"Billy is such an iconic specimen," said curator Peter Howlett.
"The Clore Discovery Centre now provides a great space to display Billy and allow visitors to see 'him' again after so many years."
The new centre has been built with the help of a £160,000 donation by the Clore Duffield Foundation.
It will store several new resources to encourage object handling and exploration in more depth than the former Glanely Discovery Gallery.
Ceri Black, the museum's head of learning, said: "Our new gallery will give people an exciting hands-on association with the past.
"Billy the Seal is a really interesting specimen from historical perspective, but we have lots of fascinating things in our museum stores.
"We try and ensure that museum displays change, so that other objects get 'air time' and our visitors have new things to discover each time they come here.
"There's been a lot of interest in the skeleton and in the video about his/her history created by Cardiff school students ... it's a story that really captures people's imagination."
A statue of Billy the Seal has pride of place in Victoria Park
The skeleton of Billy the Seal was last on display to the general public in the early 1990s.
Billy was caught in a fishing net off the coast of Ireland in 1912 and was discovered when the catch was brought back to Cardiff docks.
The animal was given a home in a pool at Victoria Park and became a popular attraction.
When Billy died in 1939 experts at the National Museum examined the body and found that "he" was actually female.
Billy is commemorated by a statue in Victoria Park.