This is the third in our series in which we ask you to identify where in London this picture was taken and what it’s of. If you reckon you know the answer, leave a comment below. We’ll reveal the answer early next week. Good luck!

Apologies for the delay in getting this answer to you (Exploring London has been on a summer break!). But if you’ve been wondering, the answer is that the picture shows a lock detail from one of the gates leading into the old Royal Naval College at Greenwich – the anchors were a clue! Congrats to Ian who guessed the location was near the Queen’s House (contained within the former Royal Naval College). Click here if you’re interested in reading our previous entry about the former Royal Naval College and Sir Christopher Wren’s role in its design.