• Regent Street is showcasing a number of architectural installations created by architects in an initiative being conducted in conjunction with the Royal Institute of British Architects (RIBA). Now in its fourth year, the Regent Street Windows project can be seen free in store windows including those of Topshop, Espirit, Jack Spade, Ferrari Store and Moss Bros until 6th May. Participating architects include Carl Turner Architects, naganJohnson architects, Gensler, Mamou-Mani, and AY Architects. Free 45 minute to one hour walking tours of the completed installations will be conducted by RIBA representatives at lunch time today, midday on Sunday and at 5.30pm next Wednesday. Prior booking is essential – email antonia.faust@riba.org for details.

• The Queen’s Orchard has reopened in Greenwich Park having been restored with the addition of heritage fruit trees, new gates, pathways and ponds. The orchard dates back to the 17th century  – its name has been found on a records dating back to 1693 and now features on a new metal decorative gate which, as well as a well cover, was designed by local artist Heather Burrell along with local school students and the Friends of Greenwich Park. The heritage fruit trees, which have a provenance dating back to the 1500s, include apple, pear, cherry, plum, peach, apricot, nectarine, quince, and medlar trees. For more, see www.royalparks.org.uk.

• The first woman to qualify as a dentist in Britain has been honoured by English Heritage with a blue plaque at her former home in Islington. Lilian Lindsay (1871-1960) lived at the house at 3 Hungerford Road, Lower Holloway, from 1872 until 1892 when she decided to become a dentist. Refused entry to the National Dental Hospital in London, she trained at the Edinburgh Dental Hospital and School (where she also met her husband Robert) before setting up a practice in Upper Holloway. Following her marriage, Lindsay relocated to Edinburgh where she and her husband ran a dental practice, only returning to London after their retirement in the 1920s. Both were actively involved in the British Dental Association. For more, see www.english-heritage.org.uk.

• A 13-year-old photographer, Gideon Knight, is holding his first exhibition, ‘Wild About Photography’, at The Temple, Wanstead Park in Epping Forest. Self-taught, Knight has drawn on his passion for bird-watching in capturing a series of images of birds and other wildlife in a range of natural environments – from the forests of Essex to the countryside of southern Ireland. The exhibition is free. Open on weekends and bank holidays until the end of June, between noon and 5pm. You can follow Gideon at  http://earlywormbirder.blogspot.co.uk.

• On Now: Patrick Heron: Studies for a Portrait of TS Eliot. On display for the first time at the National Portrait Gallery, the 10 paintings and drawings were completed in preparation for a 1949 modernist painting of the poet. They include two oil studies which have never before been seen in public. Heron secured permission to paint Eliot in January 1947 with the first sitting held two months later. Runs until 22nd September. For more, see www.npg.org.uk.