The moon makes a silver path over Tor Bay. It’s framed by clouds of steam, glowing lilac in the train’s floodlights. This is the view from my toasty carriage on the Dartmouth Steam Railway’s Train of Lights. It’s one of many things I would have missed if I’d come in summer. In winter, Devon’s trains, hotels and beaches are generally emptier. There are thousands of wading birds, crisp coastal walks to pubs, bracing moorland and Christmas lights, all easy to reach by rail if you avoid the strikes. Researchers recently found that Exeter has the greenest urban centre in Britain. And the city sits, like a picturesque spider, at the heart of a web of scenic railway lines radiating across the Devon countryside, including the newly reopened Dartmoor line. My plan is to base myself in Exeter, with its budget hotels and wet-weather options, and explore by train. The eclectic Royal Albert Memorial Museum (RAMM) near Exeter Central station is my first stop. There’s a five-metre-high stuffed giraffe and a trove of Roman money, Britain’s third largest coin hoard, found by detectorists nine years ago in a field near the sea. Then, armed with a spiced courgette sandwich from the Exploding Bakery nearby, I hop on the coast-hugging Riviera line and look out for the Norman towers of Exeter cathedral (free to visit until the end of January), from the train window. Thousands of migrating waders and waterfowl visit Dawlish Warren every winter. Twenty minutes down the railway, the sands are peppered with brent geese and plovers, and the sheltered dunes are busy with birdlife too: there’s a green woodpecker feeding on the ground, a charm of goldfinches on the pondside rushes, and several species I can’t immediately identify, including stripy brown birds that turn out to be rare cirl buntings. As I stroll the couple of miles along the coast to Dawlish to catch the train again from there, the winter waves are throwing up prismatic plumes of spray. It’s easy to see how storms washed this coastal railway away in 2014. I’ve passed this stretch of coast every year for decades, heading for Cornwall to see family, but have rarely got off. Instead of getting just a tantalising trackside glimpse of red rock formations with nicknames like Elephant Rock, today I can walk inside sea caves and under towering stacks of sandstone. The train goes on past Teignmouth, where England’s oldest ferry runs year-round across the river, and Torquay, with its miles of palms and Agatha Christie connections, to Paignton at the end of the line. A free booklet of walks from stations suggests a circuit of Paignton via harbour and headland, but the temperature is sinking fast with the sun. I opt for tea and chips on the pier, watching the seabirds and surfers braving the stormy sunset waves below until it’s time for the after-dark steam-train ride. One of the newer exhibits in RAMM, along with Covid tests and hand sanitisers made by Exeter Gin company, is a taxidermied beaver. She was one of the less-lucky participants in a thriving scheme to reintroduce beavers on the River Otter. Inspired, I catch an early train along the Avocet line to Exmouth and then bus 157 to a brick-and-thatch village called Otterton. The riverside walk from here to Budleigh Salterton is a summer honeypot for beaver-spotters, but today there are just ducks, a few dog walkers and a couple of diggers, working on a scheme to shore up the waterway against the changing climate. It’s a lovely walk, with mist rising from the egret-haunted marshes and waterside trees ringed by clear tooth marks. Back in Exmouth, I take a Stuart Line cruise on the shallow River Exe. We sail past mudbanks full of scampering sanderlings and spread-winged cormorants. These popular year-round boat trips offer hot drinks in the bar and blankets on the top deck with varied views of the estuary: paddleboarders, sunken wrecks and a grey heron flapping over a drifting mussel boat on slow, dark wings. There are local mussels for lunch at luxurious Lympstone Manor (10 minutes away on bus 57), opened by celebrity chef Michael Caines in 2017. Below Lympstone’s five-star hotel and Michelin-starred restaurant, a vineyard and immaculate sculpture-dotted lawns slope down to the Exe. This winter, Lympstone has introduced lunch for non-residents in the glass-walled Pool House (from £45 for two courses). After a deeply umami Dartmoor mushroom risotto and bread with confit garlic, I’m glad of a walk along tracks and quiet lanes between the manor and peaceful Lympstone village. A 45-minute train journey round to Starcross and three stops on bus 2 bring me to the gates of Powderham castle, where a crowd-pleasing Christmas trail winds through grounds and castle, past a walled garden with geese and goats, an illuminated maze, craggy floodlit oaks and winking Christmas trees. Daily passenger trains on the Dartmoor line, linking Exeter with Okehampton, began again in November 2021 for the first time in 50 years. A year on, the line has carried more than a 250,000 passengers. The Dartmoor Way, a 108-mile (174km) circuit of the national park, officially launched a waymarked walking route in 2022. Robins are hopping around the holly bushes as I walk through woods near Okehampton station. It starts gently snowing as I reach the ruined castle, and I follow a streamside stretch of the Dartmoor Way into the village for coffee in the Victorian Arcade and onwards to Fatherford viaduct. A walk over East hill promises a “Dartmoor taster” and doesn’t disappoint. Out of the valley’s shadows and away from the A30, I climb into powerful winter sunshine. There are views all round across granite tors, wind-bent thorns and grazing ponies. Lydford gorge is 10 miles away, and bus 118, over the moors, offers a rail link from the station, timed to coincide with trains. It stops by the gorge’s lower entrance where a trail leads to the 30-metre Whitelady waterfall. Powered by seasonal precipitation, it cascades down rocks and through the misty air. The mosses, ferns and lichens of a temperate rainforest wrap the trunks and branches. At the top of the lane in Lydford, there’s time to look at the 13th-century tower and Saxon defences and for a half of Anthem in the cosy Castle Inn. The frost-etched trees above frozen fields of sheep look like a Christmas card next morning, especially when sunrise silhouettes the bare branches and gilds the wintry hills. I’m heading for Barnstaple on the Tarka line, named after Henry Williamson’s 1920s novel about an otter. Williamson based Tarka the Otter on years of careful observation in the area. The 180-mile Tarka Trail includes the UK’s longest continuous cycle path and there is seasonal bike hire at the station. For a stylish end to the trip, I’m moving from my budget hotel in Exeter to the waterside Seagate in Appledore. There are 17 generous rooms over the old tavern and in a former sail loft nearby with views across the River Torridge (doubles from £84, room only). A Victorian charitable group called the Royal Antediluvian Order of Buffaloes used to meet at the Seagate (I learn this and much else from David Carter’s three-volume Illustrated History of Appledore). The website Great Scenic Railways has a real ale trail along the Tarka line and a foodie guide, which includes the Boathouse, where I’m having lunch, a pebble’s skim over the estuary at Instow. There’s a summer ferry and year-round, regular bus, but I walk the three miles to the Long Bridge at Bideford. The route is part of the spectacular South West coast path, but most walkers take the ferry and miss out on boardwalks across tiny wooded coves and fern-banked tree tunnels, winding down to the glinting River Torridge. Today the reeds are spiked with frost and the last leaves fall in flurries of autumn gold. This is Tarka territory and there’s a bronze statue of the otter on Bideford quay. The Boathouse has views across dunes, wide sands and water to Lundy. The menu includes fish pie with rainbow chard. Cornish scallops and smoked haddock are packed under a golden layer of brown crab cheddar mash. Bus 315 from outside the door runs direct to the gates of RHS Rosemoor. With its bright birches and dogwoods, elegantly structured gardens and varied evergreens, Rosemoor really is a garden for all seasons. The cold air smells of sage and curry plant, Christmas box and wintersweet. As darkness falls, the Glow trail opens with giant stars and incandescent forests. As I wait for the bus back, the moon is bright over the tree tops and owls are hooting in the woods.