Is this an Orchid?

Leaves look about right for a young Lady's Slipper Orchid (Cypripedium), though a few other wild terrestrial orchids have similar foliage. Most such orchids need several years to build up enough energy to bloom, so if it is less than 4 years old, I wouldn't worry too much. I would leave an open circle at least 50 cm wide, with no competing taller plants, to allow it to gather solar power. Also, I would replace the stones with several cm of good compost as mulch, and probably also use a mild organic fertilizer while it is in leaf. Those alterations will help it to mature faster.

Hi, many thanks for your reply. I would guess it's at least 10 years old. I will mulch it and feed it, something I have never done! We were told at the time it was a rare plant!

My wife now tells me it did flower once, the flower was quite insignificant and she thinks it was white!!

It could be. At least 90% of wild orchid flowers are spikes of little white things of no interest to anyone except bees and wild orchid enthusiasts. Intricate structure close up, but not the impact of a rose bush or gladiolus. Worth preserving, like any other species, though: there's no need to go popping any more rivets in "Spaceship Earth"!