Warmth has been injected into the beautiful but previously empty interiors of his 'Little Castle' with the addition of carefully researched 17th century reproduction furniture in exquisite silks and velvets in the most important rooms. In the grandest room, the Star Chamber, colourful tapestries now hang from the walls, complementing the stunning gilded blue ceiling and painted panelling.

The whole effect adds vibrancy to the Little Castle's unique wall paintings - including famously risqué scenes - lavish gilded panelling and carved stonework, state of the art decoration created by Cavendish to impress. Visitors can open 17th century-style cabinets to unlock the secrets of the castle and how it was used as an extravagant retreat for relaxing, entertainment, cultural pursuits and parties.

Outside, for the first time in over 250 years, visitors can stride along Cavendish's catwalk - the previously perilous wall-walk circling the Fountain Garden, where the cavalier and his aristocratic friends once promenaded to see and be seen. Effectively a wide elevated terrace and now repaired and complete with restored crenellations and obelisks, the walk gives panoramic views across distant countryside and into the garden below as it was meant to be seen 400 years ago.

A rare survival from the English Renaissance, the Fountain Garden has been taken back to how it may have appeared when it hosted a lavish entertainment staged by Cavendish for a visit by King Charles I and Queen Henrietta Maria in 1634. Original borders have been recreated and planted with nearly 5,000 plants - to reflect the imported, or 'outlandish,' plants that were then the height of fashion.

The garden's simple layout of paths and lawns surround another rare survival from the time - a working octagonal fountain, topped by a statue of Venus, with restored statues of Roman emperors, putti, satyrs and heraldic beasts. Fan-trained fruit trees planted against the garden wall have been added to provide interest from spring to autumn.

A final flourish is the addition of a temporary garden in the shape of a serpent from the Cavendish crest - which in the 1630s, would have been created in fanciful designs just for special occasions. Cut from turf it is filled with coloured sand in the style of the time and will wow today's visitors looking down from the wall walk as a similar creation may have impressed the king in 1634.

The Little Castle at Bolsover is recognised as one of the most important Jacobean buildings in the country. Complete with battlements, chivalric towers and turrets, it was never intended as a residence, but as a place to relax - where William and his family went to from their main residence at nearby Welbeck Abbey to entertain friends or simply enjoy the pleasures of life - banqueting, reading, writing, poetry, plays and music.

Elegant and fashionable, it was designed to impress his most sophisticated guests - friends dubbed it the 'peak of perfection' and compared it to an exquisite pearl.

William Cavendish is known for his love of 'softer pleasures', and certainly lived his long life to the full during a turbulent period in English history. As a courtier, cavalier and master horseman he lived through the reigns of three kings, taught the future King Charles II to ride, fought for the royalist cause and saw defeat in the English Civil War, lived in exile on the continent, and was twice happily married, despite his roving eye.

He was also a sophisticated and enlightened man and an influential patron of the arts, science and philosophy. Visitors can now discover these deeper aspects of his personality at Bolsover Castle, and find out more about the flourishing literary and artistic culture of 17th century England.

At Bolsover castle, visitors can now also see and enjoy:

• garden rooms sitting snugly within the garden wall. One is thought to have been used by Cavendish to conduct scientific experiments - including the creation of fireworks from salt petre and brimstone. The grandest, with seating and an ornate fireplace, has been restored and is newly open to the public
• a lively new hands-on introductory exhibition and film
• discovery boxes and family games, plus a stage in the Little Castle where children and adults can dress up and perform scenes from the play commissioned by Cavendish from court playwright Ben Jonson for the royal visit in 1634
• displays in the Riding House by superb horses showcasing Cavendish's intricate dressage techniques every weekend and Bank Holiday from April to September
• new custom-built castle themed children's play area
• complimentary multi-media guides narrated by Spooks and Silk star Rupert Penry-Jones, which can also be downloaded for free ahead of a visit