This is Saffron Close, one of the exclaves* of Sutton.
exclave, noun (plural exclaves)
A portion of a country's territory not connected to the main part.
It's a very ordinary late 20th century cul-de-sac, not far from the tram stop at Therapia Lane in the vicinity of Mitcham Common. But it has one particular quirk which is that although it's entirely within the London borough of Sutton, you can't enter or exit without passing through the London borough of Croydon. [map]
Saffron Close bears off at the junction of Alfriston Avenue and Therapia Lane, both of which are in Croydon. There are no obvious clues of a borough change, like a 'Welcome to Sutton' sign on the lamppost at the top of the road. But if you look closely the street sign for Saffron Close is of a completely different style to that for Alfriston Avenue and Therapia Lane, both of which use the lumpen typeface municipal Croydon inexplicably loves. Also you can always check the bins. This doesn't work so well now that Croydon and Sutton are both part of the same refuse collection conglomerate, but most Saffron Close householders still have the old style Sutton bins and those on the other roads are predominantly pure Croydon.
If I'm going to be really accurate, Saffron Close leads to two other shorter cul-de-sacs called Cinnamon Close and Rosemary Close. Both of these meet at the far end with bollards inbetween to prevent drivers making through journeys, otherwise they'd form a single crescent. But you can't escape into Sutton from here either, no footpaths or alleyways exist, the only way out is via Saffron Close into Croydon.
Altogether there are 53 houses in the Saffron Close exclave divided approximately equally between the three constituent streets. They're all of a decent size, some faux-timbered and others unashamedly brick. The architects didn't bother with nice front gardens, boundary fences or hedges, preferring to prioritise adequate parking space. The whole thing's a bit Beckton-y and atypical for London. It's also a bit mucky in places, so for example I know the name of the man at number 14 because some cardboard packaging addressed to him has been dumped by the street sign beside a car seat and an empty cat carrier. None of this is interesting, sorry.
What I really wondered is "why is this outpost of Sutton effectively in Croydon?" and I think it's because it was built too late.
Therapia Lane is really old, once a rural wiggle, since suburbanised. Alfriston Avenue is lined by some of those drab interwar terraces Croydon seems to specialise in. But the land where Saffron Close was built was originally light industrial - partly railway depot, partly the sports ground of a rubber works - so it didn't matter it was in a completely different borough. Most importantly Saffron Close is a 1996 development but the Sutton/Croydon boundary was last rejigged by the Local Government Boundary Commission in 1994 so they wouldn't have known it was going to be built. By such temporal quirks are exclaves created.
• Behind Saffron Close is an extensive trading estate (on the site of the aforementioned rubber works) which can only be accessed from Mitcham Road which is in Croydon.
• Beddington Lane Industrial Estate, behind Beddington Lane tram stop, can only be accessed from Beddington Lane which is in Merton.
• Sutton's northernmost street, Hillfield Avenue on the St Helier estate, can only be accessed from Bishopsford Road which is in Merton. [52 properties]
• The avenues of Cuddington spanning Banstead Road, previously blogged, are only connected to the rest of Sutton via a golf course and a private road. [280 properties]
• The Clockhouse estate, which has its own church, pub, shops and everything, is only connected to the rest of Sutton via a long footpath up Grove Lane (part of London Loop section 6). [650 properties]
• Overhill Road in Purley can only be accessed from the rest of Sutton via a footpath or via Hillcrest Road which is in Croydon. [12 properties]
There are also two exclaves of other boroughs where access is only possible through Sutton.
• Nova Mews, near the Asda on the A24, is in Merton but can only be accessed from Stonecot Hill which is in Sutton [23 properties]
• Kingshill Avenue, Hughenden Road, Risborough Drive, Pembury Avenue and Camberley Way in Worcester Park are collectively in Kingston but can only be accessed via Green Lane which is in Sutton [450 properties]
Other London boroughs have exclaves too, and I expect some of you will want to tell the rest of us about them.
* technically these aren't exclaves, they'e pene-exclaves.
pene-exclave, noun (plural pene-exclaves)
An area that is for practical purposes an exclave, but does not meet the strict definition: an area that is not completely separated from the main part, but can only in practice be reached by passing through another area. For instance, a region of a country that is not connected by road to the main part of the country without passing through another country.
If this is your kind of niche, Wikipedia has a wormholeful for you to fall down.
n.b. No need to tell us about Baarle-Hertog, 11 former commenters have beaten you to it.
