Carretera de les Aigües

Viewpoint · Collserola (Sarria-Sant Gervasi)Barcelona,Spain

Ten kilometres of dead-flat unsurfaced track cut along a Barcelona hillside to follow a water pipe, holding the whole city at one height.

The Carretera de les Aigües is ten kilometres of dead-flat track along the side of a mountain. It is a wide unsurfaced service road with no traffic and no gradient, and about two thousand people a day walk, run or cycle it. What it gives you is the city held at one height. Barcelona lies below in its entirety — the grid, the towers, the sea — and it stays there as you walk instead of appearing at the end of a climb. The line is flat because a water pipe runs under it. In 1909 Barcelona's water company built a reservoir on the ridge and cut this road to follow the contour exactly, holding one height the whole way. Inland, on clear days, the serrated ridge of Montserrat stands up above the hills. There is no shade anywhere along the track, the surface is dust in summer and mud after rain, and the whole length is unlit, so it belongs to early morning and to the last two hours of light.

Worth knowing

Good to know

The light runs along the hillside, not down it — Early and late the sun runs parallel to the track, so the city below is side-lit and every block throws a shadow.
Carry everything you will drink — there is no fountain along most of the ten kilometres and no shop of any kind, and the flat surface makes people walk much further than they planned.
Sunset and Sunday morning are busy — this is the city's own exercise route, so at those times you are sharing a wide track with runners, dogs and bicycles rather than walking alone.

Things to do

1
Set a time, not a destination
There is no destination, so pick a time rather than a place. Walk out with the city on your left, note something to turn at, and come back with the light on the other side of everything. Because there is no climb, the return is exactly as easy as the outward leg, which is unusual on a hillside.
2
Pick out your own landmarks from level
Stop somewhere with a clear view and find the towers of the Sagrada Familia, the hill with the fortress on it, and the tall coloured tower inland. From here they are all at roughly the same distance and the same angle, so the city reads as a map rather than as a skyline.
3
Arrive at first light for the quiet
Before the runners arrive the track belongs to birds and to the sound of the city coming up from below, which at that hour is mostly distant traffic and shutters. The light comes in flat along the hillside from the sea end, and the whole plain is still in shadow while you are already in sun.