It’s so dark, it makes no difference whether my eyes are closed or open. The only sound is breathing and a faint ripple when I weightlessly shift position in the salt-laden, skin-warm fluid. Inside an egg-shaped pod at Float in the Forest, one of my personal nightmares (being left alone for an hour with my own thoughts and no distractions) turns out to be a strange, peaceful experience, where time is condensed and space expands. Initially sceptical, my husband, Luke, also emerges from his pod and declares the experience “profoundly relaxing as few things are” (£60, book ahead).

We’re visiting the Forest of Dean in Gloucestershire for a car-free spring break and our hotel is a leafy 15-minute bus ride from the flotation centre. Thrice-daily bus 27 is cash only with no number on the front (just the company name FR Willetts), and people greet each other as they board. We chat to Julia, “born and bred a forester and proud of it”, who tells us: “Town people are weird. They don’t understand the slow pace of country life.” As if to prove her point, at that moment the bus detours carefully round a sheep with two new lambs suckling unconcernedly in the middle of the road.

After the float, we hike five miles through the rainy forest to the Cycle Centre. On the way, wet branches and bracken are wreathed in soft wool from free-ranging forest sheep that have wandered past. There are trees full of siskins and goldfinches, there are mandarin ducks on an old ironworks’ pond, and banks of wood anemones and primroses. The air is noisy with spring birds and smells of rich earth, churned up by resident wild boar. Underfoot there are pungent, bright-green wild garlic leaves and pine needles, all enhanced by the morning’s misty drizzle and our earlier sensory deprivation.

These woods may feel remote, but it’s quite possible to get around on foot, by bike or on public transport: there are several regular bus routes and a bookable demand-responsive minibus called The Robin. From Gloucester railway station, bus 24 runs right into the forest and stops outside the place we’re staying, 17th-century Speech House (doubles from £103 room-only). A few miles west of the forest’s main town, Cinderford, Speech House was built as a hunting lodge and forest court and is still leased from the crown. Breakfast is served in the courtroom with its stone fireplace, wall-mounted antlers, original carved oak chairs (chained to the wall since they were stolen in 2005) and copies of the 1221 Verderers’ charter over the coffee pot.

The Forest of Dean’s 42 square miles have been well trodden over the past thousand years: the Normans hunted boar here, Tudor monarchs turned its trees into warships. For centuries, freeminers have dug coal and iron ore in caverns deep underground and Verderers, appointed to protect the “vert and venison”, still meet at Speech House. Today, the storied forest is a brilliant place to walk and cycle, past mossed relics from several centuries.

From the Forest of Dean Cycle Centre, a mile from Speech House, a network of family-friendly circuits and trails crisscross the wooded slopes (pre-book bike hire from £25 or £45 for e-bikes). While I stroll around sculptures in steady rain, Luke e-bikes the Colliers trail, mostly along picturesque old railway lines, and comes back wet through but exhilarated. We sit by the Pedalabikeaway cafe’s roaring log fire in a former mining office to dry out before strolling back through the trees. The only other living things in the evening woods are birds, squirrels, and white-rumped roe deer.

In the morning Luke has to leave early, but I stroll into the trees to hear the dawn chorus and see Kevin Atherton’s stained-glass window, lit by the rising sun. Next up is a visit to Puzzlewood (open daily, £9.50/£8 for adults/children) a fantastical moss-cloaked corner of ancient woodland that has provided film locations for Merlin, Doctor Who and Star Wars. It’s a rare surviving example of the UK’s temperate rainforest, where lichens, fungi and other wildlife flourish in damp, shady gorges. Polypody ferns sprout from viridescent branches; woodpeckers hammer, and nuthatches and treecreepers patrol the trunks. Steps, bridges and walkways lead visitors through a maze of velvety scowles, a local landscape feature formed by collapsed cave systems and Roman quarries. Underneath the Forest of Dean lie 600 acres (245 hectares) of natural caves and miles of passageways.

At Clearwell Caves, 15 minutes’ walk down the road, I meet Jonathan Wright, one of the forest’s last freeminers. Jars of his carefully unearthed ochre are for sale in the gift shop, but Jonathan is slightly melancholic about representing an era that is drawing to a close. Records show freeminers have been extracting the forest’s minerals since the 13th century and documents show rights were granted long ago “unto ye miners of the Fforest of Deane”. Visitor numbers are dwindling at Clearwell, but the caves are certainly worth visiting, with displays across 10 varied caverns featuring sound recordings of now-dead miners or ghostly projections of prehistoric fish across a floodlit underground pool (£12/£10 for adults/children).

There are several options for getting to the Clearwell area without a car. The Robin will drop off visitors at the caves on demand (£2, book ahead). From Speech House, you can also catch bus 24 to Coleford, perhaps picking up a picnic at one of the shops there, such as the Crusty Loaf Bakery (great spicy veg pasty) or the Forest Deli (wild boar scotch eggs), before hiking a half-mile down the B4228 to Puzzlewood. Since the rain has stopped to reveal a celandine-speckled spring day, I opt for a five-mile circular walk via both attractions and Clearwell village.

Next morning I’m steaming south from Parkend, eight minutes away via bus 27, on the cheerful Dean Forest Railway (£16/£8 for adult/child). The train puffs down the wooded Lyd valley to Lydney Junction. From here, it’s just 20 minutes by rail to Newport along the wide River Severn, where I spend a day rambling through the flowering south Wales countryside and a night in the Old Barn Inn (doubles £99, B&B), half an hour on bus 74A or bus 74C from Newport.

From the noisy M4, I climb deep-sunken lanes up to Penhow Woodlands, now dappled with wild Welsh daffs. Bluebells flower here in May. There are iron age hillforts and views that stretch as far as the Somerset coast and, later, pub grub under 18th-century beams. Heading east by rail again next day, I get to Reading in just over an hour. There are glimpses from the train windows of the moss-walled castle by Newport station and prehistoric Uffington white horse in the chalky hills soon after Swindon.

Accommodation was provided by Speech House and the Old Barn Inn and the trip was supported by Visit Dean Wye. Train travel was provided by GWR (advance tickets Reading to Gloucester from £15.50 and to Newport from £24)