• Queen Elizabeth II this week unveiled the final plaque marking the end of the 37 mile/60 kilometre Jubilee Greenway in front of Buckingham Palace. The circular Greenway – marked by 542 glass plaques – has been created to celebrate the Queen’s Diamond Jubilee. It can be walked or cycled and takes in key sites around London, including Kensington Palace, Regent’s Park, the Thames Barrier and Olympic sites including Greenwich Park (equestrian events), the O2 Arena (hosting gymnastics, trampoline and basketball events) as well as the main stadium at Olympic Park. The Greenway is divided into 10 sections and you can download either the entire walk or brochures for one of the sections only here.

• This weekend sees the Barbican Centre play host to the event known as ‘Barbican Weekender’ – two days of free art, dance, music, theatre and film at the Barbican Foyers. Part of London 2012 Festival, the event’s ‘Freestage’ programme features Roxxxan,Dizralie and the Small Gods, young drummers from East London and performance poetry by the Barbican Young Poets. There’s also street dance classes with Boy Blue Entertainment, the chance to make an Opera in a Day with the Hip Hop Shakespeare Company, a Digital Graffiti wall, street food stalls, the Wah Nails Pop-Up boutique and free running by Streets United. For more, see www.barbican.org.uk/weekender.

• On Now – Measuring the Universe: from the Transit of Venus to the edge of the cosmos. Marking the 2012 transit of Venus, this exhibition at the Greenwich Observatory follows the story of man’s ongoing quest to understand the vastness of space, looking at the people and technologies involved in seeing farther than ever before – from the Astronomer Royal, Edmond Halley, to Captain James Cook and Edwin Hubble and through to the possibilities offered by the Cosmic Microwave Background Explorer. It’s accompanied by a series of talks, observing events – including this month’s Daytime Sky Watch sessions – and a planetarium show. Runs until 2nd September. Admission is free. For more information, see www.rmg.co.uk.