Perhaps it was the excitement of finding ourselves at a loose end on a relatively dry and clear day, perhaps it was the prospect of having our eyes scorched red by steam and our skin flayed by flying cinders, but something drew us to the UK’s highest mountain railway, and that unknowable something has a lot to answer for.

The main station and ticket office is situated in the pretty tourist trap of Llanberis, a village that offers a fine array of activities, from boat trips on the lake, to a gentle steam train ride around same, to the famous mountain chuffer that was calling us to it, like a vicious, whistling siren.

The first hint of danger came at the ticket office. Prices were high (£15 per adult, £11 per child), though we were told that under 5s could travel free as long as they didn’t take up seats. Our boys love trains, so we figured they’d endure the hardship of our laps – though even as we shelled out our hard-earned, I started to experience doubts about the logic of a 90-minute round trip beneath a wriggling child.

We were told that the train wouldn’t be travelling to the summit station, as this was being rebuilt, and that our destination was actually a piece of barren waste ground. But otherwise there was much to look forward to. Sheep, for example, and walkers, waving excitedly, or at least frantically.

As we packed into the train at the appointed time, we found that each carriage was designed to seat eight adults. Eight size zero adults. Our normal sized arses melded with those of strangers as children bobbed across our laps as if surfing a hot, angry bouncy castle. There were many, many children. If they weren’t paying, they weren’t on the radar you see, so each carriage, filled to capacity with big people, could be topped up with a handful of small ones.

On busy days you get the feeling the guards just lob a few toddlers in through the open windows in order to pack as many on board as possible.

The journey up the mountain was hot (our windows were jammed shut), the children moaned, the adults groaned and the whole experience was only lightened by the knowledge that we’d have half an hour on a barren, windswept mountain to endure before the return leg. Thomas the Tank Engine it wasn’t.

Of course all visitor attractions have the right to close areas for repairs and improvements, and they also have the right to charge for all seats. If you’re not taking kids with you, there’s an outside bet that you’ll get to enjoy some of the stunning scenery rather than pacifying screaming toddlers, but if you are taking kids – even tiny ones –  I urge you to pay the exorbitant prices and get them a seat. At least then you’ll have some breathing space.       

Sadly our experience of the Snowdon Mountain Railway left us grimly determined never to give it another chance – if only for the sake of our family’s well-being and sanity. Next time we’ll do something less cramped and stressful – do they offer holidays on the Tokyo underground?