paragraph_text: The building housed the department store Derry and Toms until 1973, and then Biba until 1975. Since the 1980s the garden has been used as a restaurant and club.

paragraph_text: Rhythm in Space is a public art work by artist Max Bill located at the Lynden Sculpture Garden near Milwaukee, Wisconsin. The abstract sculpture is a column topped by three overlapping rings with the outer edges contiguous to the inner ones; it is installed on the lawn.

paragraph_text: Presby Memorial Iris Gardens is a nonprofit, volunteer-run living museum specializing in iris flowers, located at 474 Upper Mountain Avenue, Montclair in Essex County, New Jersey, New Jersey, United States. The gardens are situated on 6.5 acres. Adjacent to the gardens is a Victorian house, the Walther House. The house is open to the public and is home to a museum shop and headquarters for the Citizens Committee that oversees the gardens.

paragraph_text: Highline Botanical Garden is a community botanical garden located at 13735 24th Avenue South, SeaTac, Washington. It is open daily without charge.

paragraph_text: Mehan Garden is an open space in Manila, Philippines. It was established in 1858 by the Spanish colonial authorities as a botanical garden, called the "Jardín Botánico", outside the walled city.

paragraph_text: The National Orchid Garden, located within the Singapore Botanic Gardens, was opened on 20 October 1995 by Singapore's Minister Mentor Lee Kuan Yew.

paragraph_text: Another important library – the University Library, founded in 1816, is home to over two million items. The building was designed by architects Marek Budzyński and Zbigniew Badowski and opened on 15 December 1999. It is surrounded by green. The University Library garden, designed by Irena Bajerska, was opened on 12 June 2002. It is one of the largest and most beautiful roof gardens in Europe with an area of more than 10,000 m2 (107,639.10 sq ft), and plants covering 5,111 m2 (55,014.35 sq ft). As the university garden it is open to the public every day.

paragraph_text: Boston Garden was an arena in Boston, Massachusetts. Designed by boxing promoter Tex Rickard, who also built the third iteration of New York's Madison Square Garden, it opened on November 17, 1928 as "Boston Madison Square Garden" (later shortened to just "Boston Garden") and outlived its original namesake by 30 years. It was above North Station, a train station which was originally a hub for the Boston and Maine Railroad and is now a hub for MBTA Commuter Rail and Amtrak trains.

paragraph_text: William Grimsey (born 21 January 1952, in Kensington, London) is an English businessman who has specialised in the food and DIY sectors, most notably at Wickes, Iceland, and Focus (DIY).

paragraph_text: Way Four is a public art work by artist Bernard Kirschenbaum at the Lynden Sculpture Garden near Milwaukee, Wisconsin. The stainless steel sculpture is an open circle that creates an orbit for two triangles; it is installed on the lawn.

paragraph_text: In 2006, the Yankees began building a new $2.3 billion stadium in public parkland adjacent to the stadium. The price included $1.2 billion in public subsidies. The design includes a replica of the frieze along the roof that was in Yankee Stadium. Monument Park, a Hall of Fame for prominent former Yankees, was relocated to the new stadium. Yankee Stadium closed following the 2008 baseball season and the new stadium opened in 2009, adopting the ``Yankee Stadium ''moniker. The original Yankee Stadium was demolished in 2010, two years after it closed, and the 8 - acre site was converted into a park called Heritage Field. The new Yankee stadium opened in 2009 and is currently used by the NY Yankees.

paragraph_text: The Georgeson Botanical Garden is located at 117 West Tanana Drive on the University of Alaska Fairbanks campus in Fairbanks, Alaska, United States. The five acre garden hosts a variety of research and educational programs in subarctic horticulture. It is open to the public during daylight hours, May through September, for a fee. It is part of the Alaska Agricultural and Forestry Experiment Station. The garden was named after Charles Christian Georgeson, who was USDA Special Agent in Charge of Alaska Investigations in 1899. Dr. Georgeson arrived in Alaska during the Gold Rush to research the possibilities for agriculture in Alaska. He surveyed the land near Fairbanks and started the Fairbanks Experiment Farm. A portion of the land was later annexed for use as the first campus of the University of Alaska.

paragraph_text: The Ballarat Botanical Gardens Reserve, located on the western shore of picturesque Lake Wendouree, in Ballarat, Victoria, Australia, covers an area of 40 hectares which is divided into three distinct zones. The central Botanical Gardens reserve in the 'gardenesque' style of the Victorian pleasure garden. On either side there are open parkland buffers known as the North and South Gardens. The Gardens celebrated its sesquicentenary (150 years old) in 2007.

paragraph_text: Elven C. Smith House is a historic home located at Williamson, Mingo County, West Virginia. It was built in 1938, in a Neo-Classical Revival / Georgian Revival style. It is a red brick building with a hipped roof and features a two-story, flat roofed portico supported by fluted columns. Also on the property is a stone retaining wall and monumental stairway in the landscaped gardens.

paragraph_text: Palasport di San Siro was an indoor arena in Milan, Italy. It was primarily used for basketball and volleyball until the PalaSharp opened in 1985. The arena held 18,000 spectators and opened on 31 January 1976. On January 17, 1985, a large snowfall collapsed the roof and the arena was closed.

paragraph_text: The museum operates from two sites within London. The main site in Covent Garden uses the name of its parent institution, sometimes suffixed by "Covent Garden", and is open to the public every day, having reopened in 2007 after a two-year refurbishment. The other site, located in Acton, is known as the London Transport Museum Depot and is principally a storage site that is open on regular visitor days throughout the year.

paragraph_text: Garvan Woodland Gardens is a 210-acre (850,000 m²) botanical garden located at 550 Arkridge Road, approximately 6 miles from Hot Springs National Park in Hot Springs, Arkansas, United States. Owned by the University of Arkansas, it has the stated mission of education, research and public service. For an admission fee, it is open daily, except on Thanksgiving Day, Christmas Day and the month of January.

paragraph_text: The Jardin botanique de Sedan is a botanical garden and city park located on Philippoteaux Avenue beside the Place d'Alsace-Lorraine, Sedan, Ardennes, Champagne-Ardenne, France. It is open daily without charge.

paragraph_text: Dallam Tower is a grade I listed country house in Beetham parish, near Milnthorpe, South Lakeland, Cumbria, England. It is a member of the Historic Houses Association but is not open to the public except for occasional charity events, visits to the garden through the National Gardens Scheme, and as a wedding venue.

paragraph_text: Cullen Gardens & Miniature Village was a popular tourist attraction in Whitby, Ontario, Canada. Officially opened in May 1980 by founder Len Cullen and his wife, Connie, the Gardens were a major tourist attraction in Whitby for 25 years.

Question: When did the roof gardens above the birthplace of Bill Grimsey open to the public?
Answer: 1980s