A private museum which has not been seen by the public for 40 years is opening up its strange collection.
The little-known Alfred Denny Museum, at Sheffield University, includes strange items from the world of natural history such as the skull of an extinct man-sized eagle, half a dolphin, tiny flying dinosaur skeletons and sun spiders complete with ferocious, poisonous jaws.
Many of the exhibits have never been seen by the public before.
It is being opened-up as part of the Festival Of The Mind, which is bringing leading academics from the university together with a range of artists to bring their research to a wider audience.
The museum was founded in 1905 and is used to teach students in biology and related fields.
Its curator, Professor Tim Birkhead, will be providing a series of tours for interested outsiders.
Prof Birkhead will also be outlining the story behind the museum's treasure in a talk called The Cabinet Of Curiosities, which he will deliver in a rare Belgian circus tent made with stained glass windows and wooden pews.
In another Festival Of The Mind event, called Animal Magic, Prof Birkhead is teaming up with contemporary artist Paul Evans to create a series of giant 8ft bowerbird nest structures around Sheffield.
Once built, artists will be stationed in the human-sized bowers - which in nature look remarkably like human-built huts adorned with trinkets - transforming them into full-scale interactive art pieces.
Prof Birkhead said: "This is a great way to show the public just how amazing nature can be.
"Not many people know about bowerbirds, and even fewer can believe that birds can build such sophisticated structures.
"Science might seem dull on paper but it really is quite remarkable and this is a great way of getting it out of the textbooks and into people's imaginations."
The 11-day Festival Of The Mind will feature 56 events across the city and starts today. It was the idea of Sheffield University's head of cultural engagement and festival producer Vanessa Toulmin sculptor Anthony Bennett.
Professor Toulmin said: "The talks and exhibitions will all be accessible but will never over-simplify complex thinking.
"The academics involved in The Festival Of The Mind don't want to patronise, they want to educate.
"But to help do this in a novel way, about half of the researchers, doctors and professors taking part have teamed up with the city's creative community to help bring their subject to life."
Events will include the real-time production of a piece of giant installation art, painted by robots that have been programmed by Dr Tom Stafford and artist Mattias Jones to respond to an algorithm based on the flight pattern of bees.
Prof Toulmin said: "The Festival Of The Mind will see some of the world's leading thinkers engaging with their local communities.
"It could easily become a template for other universities both in the UK and internationally to mirror.
"If there is any perception now that the university doesn't engage with the city, then there certainly won't be by the end of the month."
Sheffield University vice-chancellor Professor Keith Burnett said: "My father used to say that the richest people in the world are those who take pleasure in ideas.
"Our university and our city are overflowing with ideas.
"Now, with Festival Of The Mind, we have the perfect opportunity to come together and celebrate that."