
Sixty-one little green huts were constructed in the late 19th century as places where Hamsom cab drivers could take a break and shelter from the elements whilst swapping stories with other cabbies. These mini-community centres also dissuaded the drivers from dispersing into nearby drinking establishments.
All you need to know about these marvelous little green tardises can be found here.
Of the 61 original huts there are now only 13 left and some are shown here:

It's not often possible to go inside the huts unless you are a cab driver but when they are open most will serve a cup of tea through the hatch and it's a great way to hang out with the people in the know.