The steep slopes of Constitution hill are set to welcome the Tour of Britain to Wales this afternoon, and the short 293 metre climb could prove disproportionately important as the rain is currently soaking the cobbled road.
The riders hit the base of the one-in-four climb with two kilometres to go. If the bunch hits it all in one piece, the chances are it won't stay together for long. The rain has been falling in Swansea all morning and there's little sign of it easing up.
If the cobbles are wet when the race arrives, expect wheels sliding out and riders unclipping and running up in their cleats.
Once over the top, the riders drop back down in to the centre of Swansea for the finish, and there isn't enough time for any dropped riders to take back time. Positioning at the front of the peloton on the climb will be crucial, making the run in to Swansea the most important ten minutes of today's stage.
Race leader Greg Henderson will have to be alert. The Kiwi sprinter should be able to get up the climb with the leaders, but will need his Sky team mates around him in case he does encounter any difficulties.
When the PruTour came here in 1999 it was Raimondas Rumsas who won. The Lithuanian, who retired from cycling after a large amount of performance enhancing drugs were found in the back of his wife's car, attacked over the cobbles and stayed away to the finish. Jens Voigt was second.
Today's stage will be shown on ITV4 at 7pm.
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The cobbles are getting a soaking in Swansea which should make the short climb even more important to the race's outcome.
Just like Belgium, cobbles await the riders in Swansea.
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