Just outside London sits Windsor Castle, and within its grounds is Frogmore House, which is only open to the public on a few days of each year.
Built in the 17th century, Frogmore became a royal residence in 1792 when George III purchased it for his wife, Queen Charlotte. Since then successive monarchs have enjoyed the tranquil surroundings and delightful interiors. Although no longer an occupied royal residence, it is frequently used today by the Royal Family for private entertaining.
The gardens at Frogmore House were first laid out for Queen Charlotte in the 1790s based on a model ‘picturesque’ landscape. The design and planting schemes seen today incorporate additions made during the reigns of Queen Victoria and Queen Mary. Trees and shrubs, presented on the occasion of Her Majesty The Queen’s Silver Jubilee in 1977, have been subsequently added.
Today, visitors can enjoy gentle garden walks and views of Queen Victoria’s Tea House, the white-marble Indian Kiosk, and the 18th-century lake.
Frogmore House Garden is open on 3, 4 and 5 June in aid of the National Gardens Scheme, The Leprosy Mission and Parkinson’s UK. Tickets to visit Frogmore House cost £6.20 and will be available to purchase on the day, or online here.
It will also be open on 25th, 26th & 27th August, but the cost rises to £9 per adult that week.
All those days are mid-week. They don’t have any weekend openings.
You might want to correct the info on August 2015 opening times. Their website says 25-27 August:
http://www.royalcollection.org.uk/visit/frogmorehouse/plan-your-visit