OLDEST - purely residential street with its original buildings all surviving intact in Europe.
Posted by: 
greysman
N 51° 12.691 W 002° 38.622
30U E 524887 N 5673407
This is Vicars' Close, planned in the mid-C14th and completed in the early C15th, north of the Cathedral Church of St.Andrew in the city of Wells in Somerset.
Waymark Code: WMPYKG
Location: South West England, United Kingdom
Date Posted: 11/11/2015
Views: 4
The houses were built as homes for the priests serving the cathedral as the Vicars Choral, their duty being to chant divine service eight times a day. There were originally 42 houses each some 20ft by 13ft (6.1m by 4.0m) in plan with two storeys each with a fireplace in the front wall built along two sides of a street to the north of St.Andrew Street, north of Wells Cathedral. The fireplaces led to a two-flue stack which were heightened in the C15th possibly when coal was introduced as fuel instead of wood. About the same time the requirement for celibacy amongst priests came to an end, at the Reformation, and some of the adjacent houses were knocked into one to permit family use, some had rear extensions, and the gardens were added to the front of the properties. Lead piping was installed, by 1468, to bring water to the houses, the supply was originally from two wells one at each end of the close and these continued to function until the C19th. Number 22 is the one house which still has most of its original medieval structure as it was originally built.
The date of some of the buildings is unclear but it is known that some had been built by 1363 and the rest were completed by 1412. There were originally 42 houses each for one vicar, however in a charter of c.1582 Queen Elizabeth restricted the number of vicars to twenty, and the Vicars Choral currently number twelve men.
Many of the original windows were replaced in the 18th century and Shrewsbury House, towards the 'top left', is architecturally different to all the other buildings having been re-built in the 19th century after a fire that burnt down the original structure.
Completing the Close at the north end is the chapel built between 1424 and 1430, the lower floor being a chapel, and a library above accessed by a spiral stair. The chapel was dedicated to the Assumption of the Blessed Virgin Mary and St Katherine. At the south end is the Vicars' Hall and gateway, comprising a pedestrian gate adjacent to a waggon gate leading from St.Andrew Street. The Hall was the first part of the Close to be built, a first floor barrel-roofed common hall above a store room, kitchen and bakehouse and completed in 1348.
The above is a part extract and rewrite of the full information in Wikipedia which can be found here:- Vicars' Close