It was originally attached to Gray's Inn, which is one of the four Inns of Court. The Inns of Chancery fell into decay in the 19th century. All of them were dissolved, and most were demolished. Staple Inn is the only one which survives largely intact.
Staple Inn dates from 1585. The building was once the wool staple, where wool was weighed and taxed. - from Wikipedia
In the centre of the building above is an archway through which I found this charming square.
There is a plaque on the wall that says the following:
I think its brilliant to have such history available to view and enjoy every day.