Our route took us through the Yorkshire Dales National Park via Horton in Ribblesdale.

We stopped at the roadside parking and this was the view back as we started our short walk to the viaduct

The area is famous for the Three Peaks Challenge, which involves walking all three of the highest peaks within twelve hours.

You can begin to see the she size of the challenge, as that fell in the distance is Pen-y-Ghent, one of the three big summits.

The impressive stone viaduct on the Settle to Carlisle Railway stretches across the valley ahead.

The second of the three Yorkshire Peaks is Whernside, some 2392 feet (736 m) high, cab be seen behind it.

Dylan and Dougal provide me with a little foreground interest.

- - - o o o - - - The third peak is Ingleborough, its distinctive escarpments hidden from view apart from glimpses through the arches. . The 3 Peaks Challenge is 24-miles (38.6km) round trip route and includes 1585m (5200ft) of ascent. - - - o o o - - -

But we've chiefly walked over to marvel at the grandeur of this iconic railway bridge

The Viaduct has twenty-four magnificent arches that carry the railway line 104 ft above the moor.

[ An adventure group have parked by the viaduct, but the youngsters were enjoying their activity with their feet firmly on the ground.]

It was a classic piece of Victorian engineering, built between 1870 and 1875 but nearly closed in the 1980's.

It provides as important north south rail link and so was saved from closure and renovated instead.

It now also forms an important tourist route favoured by steam enthusiasts worldwide.

It is the longest and third tallest structure on the Settle-Carlisle line.

Suitably impressed by the structure, the size of the limestone masonry and the location, we turned and headed back to the car.

- - - o o o - - -

The railway heads north over Blea Moor, through a long tunnel and then skirts the Dent Valley, heading north.

Our route however, turns west and passes beneath another impressive railway viaduct, on the way back to Sedbergh and the M6.