Something strange slithered here

This beautiful little packhorse bridge carries the footpath over Thorsgill beck beside Egglestone abbey in Teesdale. It probably dates from the 17th. century and countless feet must have passed over it since it was built. But when you stand on the top there is evidence of something else that slithered over its stones, around 300 million years ago.

One of the capstones carries this strange serpentine marking. Some long-extinct invertebrate left its trail when it wriggled across the tropical sea floor back in the Carboniferous, before the sediment turned to limestone.

Meadow saxifrage

Thursday's Guardian Country Diary is all about this very attractive little flower, meadow saxifrage Saxifraga granulata. It's a species of meadows and pastures that has been in continuous decline for decades thanks to the 'improvement' of old grasslands with fertilisers and selective herbicides, which favour grasses and lead to a decline in wild flower diversity.

Fortunately there are still a few places in Teesdale where you can see it in profusion and one of the best sites is in the meadows that surround ....

.....the ruins of Egglestone Abbey in Teesdale.

You can read more about the history of the abbey by clicking here.

Meadow saxifrage thrives on the slopes leading up to the castle walls....

...... covering them in a haze of white flowers ...

..... and merging into the buttercups in the meadow below.

The most picturesque way to approach the abbey is via the footpath that runs over this tiny packhorse bridge, next to a more recent road bridge.

The packhorse bridge spans Thorsgill which flows into the river Tees about fifty metres downstream from this point.

The view from the bridge, along this little valley, can't have changed very much since the White Canons, who worshipped in the abbey, last passed this way over 500 years ago.

The valley has a fine population of meadow saxifrage too. It tends to grow in dense groups in the grass because it produces clusters of tiny buds called bulbils (the granules that the specific name granulata refers to) when the flowers and foliage die down in July, so when they sprout next year a whole group of plants grow up where only one existed before. The bulbils are also carried around in mud on the feet of cattle, which unwittingly plant it in their footsteps.