THE city's best-loved museums and gardens are preparing for their biggest summer ever.

As part of its 'mindgrowing' campaign, Oxford University is planning a bumper series of events aimed at tourists and families.

Visitors will be encouraged to tour all of its top venues, with children given special 'passports' that can be stamped at each one.

Those taking part include the Ashmolean Museum, Bodleian Library, Botanic Garden, Harcourt Arboretum, Museum of the History of Science, Museum of Natural History and the Pitt Rivers Museum.

In July and August alone there will be nearly 40 activities taking place, ranging from an Alice Day picnic to an Anglo-Saxon and Vikings weekend, as well as a lessons in Morse code.

Professor Anne Trefethen, pro-vice-chancellor for gardens, libraries and museums, said it was part of efforts to display more of the university's 'treasure trove' of historical and natural collections to the public.

Across all of its institutions, the university looks after more than 20 million objects which are preserved for research and education.

Prof Trefethen said: "Our collections have a breadth and historical depth you just don't find anywhere else – the first museum, the first botanical garden – and that really allows you to tell stories that cross generations.

"There is so much going on at Oxford's museums, libraries and gardens and we now have record numbers of people coming in.

"The university is sometimes seen as an elite organisation but actually we want people to come and visit us because these collections are for everyone.

"We hope our summer programme, which is aimed at people of all ages, will encourage even more people to visit our institutions."

The university's new campaign has led to a 20 per cent rise in visitor numbers, the pro vice chancellor added.

Combined, its museums, gardens and libraries attract more than three million visitors a year.

"It is extraordinary, really," Prof Trefethen added.

And the university is trying to find new ways to show people the vast range of objects it holds.

Prof Trefethen said new technology had allowed exhibits to be brought to life on people's smartphones, with visitors to the Museum of the History of Science able to try out scientific instruments in virtual reality.

In the Ashmolean museum, meanwhile, they can hear what obscure instruments on display would have sounded like.

She added: "It is allowing us to do all kinds of new things and we are looking more and more at how we can use virtual reality as well.

"That is something both children and grown-ups can enjoy together, which is wonderful."