The Ostler’s Hut is a tiny, Grade II-listed structure in Lincoln’s Inn, one of London’s historic Inns of Court near Chancery Lane. Built around 1860, it served as a shelter for the ostler, who tended horses for lawyers and visitors before cars made the role obsolete.
The hut sits at 10 Old Square, WC2A 3SU, tucked away in Lincoln’s Inn’s courts. Originally the lodge had a seat and a fireplace, measuring  only 13 by 10 feet, earning claims as London’s smallest listed building (though debated against Trafalgar Square’s police post- I painted this one also)
 
Interesting facts...
Look to the chapel next to the hut to see damage created by WWI zeppelin