On a high: Wild camping in Wales led to a quest to try other 'Extreme Sleeps' / Phoebe Smith

Phoebe Smith has camped alone in some of Britain's most dramatic spots. It all started with a trip to the Welsh national park, she explains

'What if you get mugged or eaten by a bear?" cried my friend Jane as I packed my car for the journey ahead. Her suggestion was ridiculous for two reasons. The first is obvious: I was heading to north Wales, not North America. No bears of any variety were likely. The second is that if you take a minute to think about all the muggings that have been reported in the past 20 years, very few of them happened in the middle of the mountains of Snowdonia.

The reason for her apprehension was that this was to be my first solo wild camp – a night out in the hinterland of Snowdonia National Park. Up to now I'd always been with someone else – but this was to be an initiation for me, to prove to myself that I could survive sleeping out in the wilds, alone.

I hadn't always loved spending nights under canvas – once I preferred the comfort of a warm bed and a flush toilet. But then I went travelling for two years and began to try activities that I never would have done on my home soil.

I camped out under "swag" in the Australian outback, braving snakes and poisonous spiders; I bedded down on top of the highest mountain in America's Death Valley after climbing in temperatures of over 40C and battling against 40mph winds; and I'd snuggled up in a tent in the Arctic Circle in winter at temperatures well below freezing. It was only fair to check out just how wild an adventure could be had in the UK.

Rain pelted down on the windscreen as I set out on the motorway. I was braced for the cold and wet, having packed waterproofs and extra warm layers. What I didn't expect was that this would swiftly change to blistering sunshine. Soon after leaving my car, as I reached the top of my first peak, I began to think that maybe I should have brought suncream.

After a few hours of exploration I decided to make for my campsite – a section of flattened ground next to a small mountain lake. All that was required was for me to get there. Bracken and long grass made the journey tricky, midges began to attack in swarms and as I finally emerged on to something that resembled a rough track I was confronted with a sheep.

"Hello, little sheep!" I called, already imagining the start of a great friendship. I'd feed him scraps of my camping meal; he'd sit beside my tent like a big woolly guard dog, protecting me from any intruders.

"Baa! Baaa! Baaaaaa!" Or not. He began to come towards me. Fast.

It seemed a ridiculous scenario. My friend had worried about bears, when sheep were in fact the problem.

I outran it eventually. The pulling out my tent, I pitched camp for the night, and sat checking out what would be my bedroom. Beneath my feet, a grassy carpet lay like a padded mattress on the ground. Above me rose a peak studded with heather and rock – the biggest, grandest headboard you could ever hope for.

I spent the evening cooking and congratulating myself on a great find. As the sun began to set, I sat on a rock by the water's edge.

Everything was completely still. The air glowed auburn until the moon began to rise. I spent several minutes doing nothing at all: what I saw here rivalled anything I'd experienced overseas.

Crawling into my sleeping bag, I thought I saw an odd kind of tiny spider. I picked it up but it fell through my fingers. I spent a few moments looking for it, and then – too tired to care – I lay down and drifted off to sleep.

I awoke to footsteps. Despite my pre-trip assurance, I was convinced this was "it". I felt around for something I could use as a weapon. Finding only a spork (a plastic fork-spoon combination), I peeked above the edge of the flysheet and turned on my headtorch, holding my breath.

It was back. Satanic eyes with black slits running down the middle reflected back at me. It took all my willpower to stifle a scream. "Baaa!" my nemesis cried.

I turned off the torch and slid down into my sleeping bag. The sheep pounded the ground for a few minutes. I lay there, willing it away. Somehow I fell back to sleep, and though I woke a couple of times to rabbits digging by my door, I made it to morning. Unzipping my tent door I emerged from my canvas cocoon feeling like a million dollars.

A wave of adrenalin shot through me: I had done it. I had camped alone and survived.

On my way back to civilisation, I discovered that the tiny spider from my sleeping bag had actually been a tick, a tiny blood-sucking parasite that I would later have to remove. But despite that, I felt elated. And so began a peculiar kind of addiction.

After Wales, I started to do what I call extreme sleeping: bedding down in some of the wildest places, often under a tent but sometimes without. I set out on a journey to find more wild sleeps.

I've slept on clifftops on the south coast and on hilltops in Lancashire; in caves in the Lake District and in bothies and beaches in Scotland. The best thing about it is that anyone can do it: all it takes is a thirst for adventure. Sometimes, for a real journey, there really is no place like home.

Phoebe Smith is author of Extreme Sleeps: Adventures of a Wild Camper (Summersdale £8.99).

Snowdonia Treats

Plas y Brenin

Shake off your fears and prepare for the heights at the splendid National Mountain Sports Centre outside Capel Curig (pyb.co.uk).

Snowdon Sherpa bus network

Cheap, reliable midi-buses provide public transport and a fabulous support service for hikers from Llanberis to Porthmadog, offering fine views (bit.ly/SnowSher).

Llyn Anafon

This mountain lake, pictured, makes an idyllic setting for a picnic after a summer morning's walk from the coast – so long as the water hasn't ebbed away, as happened five years ago (bit.ly/Anafon).

Welsh Highland Railway

Wales has the world's densest concentration of heritage railways and the most recently restored has rolling stock as impressive as the views (whr.co.uk).

Idwal Cottage youth hostel

The first YHA property in Wales offers comfort and conviviality in a gorgeous setting. For something a couple of notches up from wild camping, this is ideal (bit.ly/IdwalYH).

Simon Calder