Image copyright Getty Images Image caption The Art Fund prize is worth £100,000 to the gallery

The open-air Yorkshire Sculpture Park has been named the museum of the year.

The judges described it as "a truly outstanding museum with a bold artistic vision".

The park, situated in the grounds of Bretton Hall in Wakefield, was first opened to the public in 1977.

Picking up the £100,000 prize, founder Peter Murray said: "We've tried so hard to develop something which is unique not just in this country but also in Europe and beyond.

Media playback is unsupported on your device Media caption Founder and executive director of Yorkshire Sculpture Park, Peter Murray, speaks to Tim Masters

"This award makes us feel we are moving in the right direction."

The park has held exhibitions for the likes of Eduardo Paolozzi, Lynne Chadwick and Ai Weiwei. Its collection of works by Henry Moore is one of the largest open-air displays of his bronzes in Europe.

The museum of the year shortlist included the Hayward Gallery and the Tate Britain in London and the Ditchling Museum of Art in East Sussex.

The winner was announced by theatre and film director Sam Mendes at the National Gallery in London on Wednesday night.

Yorkshire Sculpture Park

Yorkshire Sculpture Park opened in the grounds of Bretton Hall College near Wakefield in 1977.

The 500 acres of parkland and gardens are home to sculptures by Henry Moore, Barbara Hepworth and Anthony Caro, while the venue also has several indoor galleries.

It has won praise in recent years for major exhibitions by artists including Joan Miro, Jaume Plensa and Yinka Shonibare.

Shonibare, who exhibited there last year, recently nominated it as his favourite exhibition space, saying it was "one of the only spaces in the country where you can properly show things both indoors and outdoors".

In May, Chinese artist Ai Weiwei opened his first UK public exhibition in four years at the venue. His works are being shown in and around an 18th Century chapel, which has recently had a £500,000 refurbishment.

It is home to Arts Council England's sculpture collection.

Founder Peter Murray was awarded an OBE in 1996 and a CBE in 2010.

Fans include Monty Python's Michael Palin and rapper Dizzee Rascal, who visited the venue while on tour. In 2011, he named it as one of the places that inspired him the most, saying the sculptures were "like nothing I'd ever seen before", adding: "The contrast between the natural surroundings and contemporary structures is stunning."

"A perfect fusion of art and landscape, the Yorkshire Sculpture Park has gone from modest beginning to one of the finest outdoor museums one might ever imagine," said Art Fund director Stephen Deuchar, chair of the judges.

"In 2013 it really came of age - with art projects such as Yinka Shonibare's extraordinary exhibition; the fruits of the expansion and consolidation of the landscape on both sides of the lake; and with the conversion of the chapel to house (as its inaugural exhibition) a major new work by Ai Weiwei."

Skyfall director Mendes said: "The dedication, love, and unbelievable creativity of the six candidates for the Art Fund prize for museum of the year are clear for all to see, as is the creative health of the UK museum community as a whole.

"Financial health is a different matter, however - and in that respect this award is a crucially important boost to one deserving organisation."

Murray, who still serves as Yorkshire Sculpture Park's executive director, told the BBC after his win: "We started with £1,000 and no staff. I did sense that we were onto something in 1977 because the landscape is very special."

He added: "We want to use the money to continue to support young artists and provide open access to the park."

Image copyright Reuters Image caption The chapel at the Yorkshire Sculpture Park is currently housing an Ai Weiwei exhibition

Image copyright Getty Images Image caption Moore's Draped Seated Woman is on loan to the park

Image caption A series of sculptures by Barbara Hepworth called Family of Man in the open air at the Yorkshire Sculpture Park

Image caption The Walk of Art features the names of people who have contributed funds to the Yorkshire Sculpture Park

The other shortlisted museums:

Ditchling Museum of Art and Craft: Ditchling became a hub of creativity after sculptor Eric Gill moved there in 1907, followed by other artists and craftspeople. Two local sisters opened a museum in 1985 and a £2.3m revamp put it on the national map last year.

Image copyright Marc Atkins

Hayward Gallery: The judges said the Hayward had an "exceptional year" thanks to exhibitions like Light Show and Alternative Guide to the Universe at its South Bank home, plus touring exhibitions by Turner Prize winners Jeremy Deller and Mark Leckey.

Image copyright Marc Atkins

Mary Rose Museum: This £35m museum was built to house the remains of the Mary Rose, a warship launched by Henry VIII in 1511. The judges said the museum "demonstrates excellence, innovation and imagination in the presentation of a truly unique artefact".

Image copyright Marc Atkins

Sainsbury Centre for Visual Arts: Part of the University of East Anglia, this venue expanded last year with new facilities designed by its original architect Norman Foster. It doubled its annual visitor numbers in 2013.

Image copyright Marc Atkins

Tate Britain: 116 years after it opened, the oldest parts of Tate Britain have undergone a £45m refurbishment, while its collection has had a major rehang to arrange the paintings in chronological order. There has, however, been criticism of its director Penelope Curtis.