|Location Map ( geo)|
|From:||Pembroke Dock (SM960035)|
|Distance:||14.2 miles (22.9 km)|
|Meets:||Dock, B4322, A477, B4322, B4320, B4319, A4075, B4584, B4585, A4218, A478|
|Former Number(s):||A477, B4321, B4319|
|Old route now:||B4322|
|Route outline (key)|
We begin (or end) at the Pembroke - Rosslare ferry terminal, before going through the northern edge of Pembroke Dock to meet the A477 at Waterloo. To our left is the Cleddau Bridge, ahead the A477 to St Clears (and the wider world via the A40. Instead, we swing right and head south, meeting the B4322 before entering a brief rural environment.
We then enter the town of Pembroke. Despite being the namesake of Wales's sixth largest county, Pembroke is smaller than Haverfordwest or Pembroke Dock. It has a one-way system of sorts, but heading south we take the short cut and only meet the A4075 (if heading north we dart round the edge of town past the B4319 and B4320) and then pass under the railway line and into countryside again).
After a mile or so we reach the village of Lamphey. We make an abrupt right over the railway line (this becomes a habit) and then an abrupt left while the B4584 continues to Freshwater East. We are now in the Pembrokeshire Coast National Park, and pass through the small villages of Hodgeston and Jameston. A mile after Jameston, the B4585 turns off to the right for the village of Manobier (with its well preserved castle and beach) before rejoining us at Shrinkle another mile on. Through the scattered settlement of Lydstep we go before we pass under the railway bridge in a really tight turn (HGVs beware!). We then go round the south of Penally (which isn't in the national park), before heading north for the first time.
We are now entering Tenby, where first a relief road for the B4318 goes off to our left. Then, almost underneath a railway viaduct, we meet the A4218, which takes off the majority of our traffic, as the only way now is further in to Tenby. From this point on, Tenby's one way system means there are two distinct A4139s, which eventually meet, with the primary A478, at South Parade Close. Here the only options are Tenby's walled town, the A478 to Narbeth, or simply to head back to Pembroke Dock.
The A4139 came into existence around 1930 when the B4321 was upgraded to Class I status; this was a short road starting on the A4075 in Pembroke and heading northwest to the A477 in Waterloo. Then in 1935 the road was extended east along what was the B4319 into Tenby. There have been a few small upgrades to this route over the years, particularly in Tenby.
By the 1970s the road had been extended west into the docks, by taking on the B4322 through Pembroke Dock. In more recent years the road has been given its own route into the docks, taking on a short section of the A477 which was vacated when the Cleddau Bridge was built, followed by a new road west. The B4322 has regained its number as its route is no longer needed.