This road junction has two interesting buildings. There is the tollhouse, pictured above, and also a former lodge of Northwood Park. Both buildings are in the same style, but the English Heritage listing pages are a little unclear if they were built at the same time, the tollhouse being dated to early 19th century and the lodge given a date of 1837.
The buildings face each other across a slightly awkward roundabout / t-junction combination. Older maps show that it used to be a more conventional crossroads with the lodge controlling access to a diagonal route across the park and on to Northwood House.
The pictures below were taken in May 2012.
Both buildings and the junction: