The Cincinnati Zoo and Botanical Gardens has announced plans to build a US$12m (€10.8m, £7.9m) expansion of its gorilla habitat.

The exhibit first opened in 1978 and was unique at the time, becoming the world’s first barless outdoor gorilla exhibit.

The large indoor space will act as a giant greenhouse, around the same size as the existing outdoor area. The new indoor area will help the zoo in areas such as husbandry and improved care, also allowing the zoo to show gorillas every day of the year as previously that was impossible due to the cold winter climate.

“The expansion helps us tell the gorilla story,” said Thane Maynard, director of the zoo. “We can tell the story of wildlife in the wild, their natural life and what it takes to protect them for the future.”

The zoo says it's hoping to have the new indoor part of the facility open by June 2017, following in the footsteps of its US$8m (€7.2m, £5.3m) hippo habitat, currently under development by HGC Construction.