I've picked this spot because Noor-un-Nissa Inayat Khan is commemorated nearby for her service in the Special Operations Executive in World War II. I didn't know anything about her until recently, but having learnt her story I wanted to share it with others.
She was born in Russia, the princess of an exiled Indian royal family. She spent her early days in this area, but the family moved to France when she was six, and most of her childhood was spent there. They fled back to England when German troops invaded France. The family has a history of pacifism, but she and her brothers and sister wanted to do what they could for the war effort, and she signed up with the Women's Auxillary Air Force - initially they refused her, but she wouldn't take no for an answer! She was trained as a wireless operator, going by the name Nora Baker to make it easier for her colleagues to say and remember her name...(sigh).
Her radio skills and fluent French led to her recruitment to the Special Operations Executive and she was the first woman radio transmitter to operate in Nazi-occupied France, using the code name Madeleine. It was extermely dangerous but essential work - the operators had to transport heavy equipment (hiding it when not in use), identify a suitable location from which to transmit - ensuring the aerial was as high as possible, to maximise the chances of success - in order to send and receive messages to the UK to aid resistance efforts. The risk of detection was high and many operators were captured - at one point she was told to return to London, such was the danger, but she refused to return, as she was the only radio operator still left in Paris. She was betrayed, captured and interrogated, but did not reveal any information about her fellow agents. Her attempts to escape were thwarted - on one occasion she and other agents got onto the roof, but an air raid alert meant their disappearance was noticed more quickly than would have been the case otherwise. She was held in solitary confinement as a 'night and fog' (disappeared) prisoner in Germany for ten months before being transferred to the Dachau concentration camp, where she and three other female agents were executed. Her final word was 'Liberte'.
She was posthumously awarded both the Croix de Guerre with Gold Star (the highest French civilian honour) and the George Cross - one of only a handful of women to receive the latter. Her George Cross is on loan to and on display the RAF Museum in Hendon currently - Colindale is the nearest Tube station.
In addition to the bust in Gordon Square, there is a blue plaque at nearby 4 Taviton Street.
The park is open every day apart from Christmas Day between 8am and 8pm or dusk, whichever is earlier. There's an information board about flora (including bluebells) and fauna in the park on the Endsleigh Place side, while the entrance by Woburn Square provides details of the Bloomsbury Group. There's also a small cafe at that end. There is an Adventure Lab around the square.
You're looking for a magnetic nano. It won't stick to everything so please replace it as found. Tweezers or a pin may be handy for getting out the log (but you won't need any tools to retrieve the cache itself! It shouldn't be inserted inside anything. There's at least one 'spare' nano now in the wrong place.
Congratulations to pantadeusz for a very speedy FTF! and congratulations to Globetrotter171 for their 8,000th find (wow)