In Southern Snowdonia, Golden Hues and Barmouth Bridge Views

"You could make a fortune if you found a way of extracting the gold," our skipper John confides. We are travelling by RIB from the Welsh seaside resort of Barmouth up into the Mawddach Estuary. Despite the 19th century mining boom, some gold still remains, deep in the seams. Nuggets are occasionally discovered in the eight-mile estuary, and Clogau gold has been used for various royal wedding rings.

It is a glorious sunny evening — not yet golden hour, but you wouldn't know it because the water and the imposing Cadair Idris mountain (named for a legendary 7th century giant, not Mr Elba) are lit up in rich yellow and russet tones. The Mawddach's fast-changing tides mean that Mawddach Boat Rides run somewhat irregularly but if you time it right and the weather is fine, you will be assured a beautiful ride. For a more active Mawddach jaunt, SUP Barmouth runs stand-up paddleboarding sessions.

Just before we reach the Farchynys headland, we turn round and return to port, passing under Barmouth's iconic railway bridge, which celebrated its 150th birthday last year. The bridge is one of the reasons my dad booked us into Aberamffra Cottage for the week: the generous terrace provides panoramic views of the bridge at all times of day. Turning to the east, you can see more of the estuary, the surrounding hills and mountains, and the gothic manse known as the Clock House. The cottage has two bedrooms and a 'bunkhouse' one floor down, which is surprisingly cool, even on a hot summer's day, as, like much of Barmouth, it is built directly into the cliff.

It's a short walk from Aberamffra to downtown Barmouth — Abermaw, in Welsh, or Y Bermo, more informally. For a small town (the winter population numbers about 2,500), the high street is impressively bustling. As well as the expected collection of beach and gift shops, and second-hand book and antiques shops, there's the hip Pieces for Places, which sells a variety upscale and/or upcycled homewares. Speciality coffee hasn't yet hit its stride in the town, although Bradshaw's, with locally roasted coffee from Poblado Coffi, is probably your best bet. And for fish and chips, look no further than the Harbour Fish Bar; you may have to queue on busy evenings, but the crispy battered cod is worth the wait.

I've been to Barmouth many times before but never in the height of summer. Visiting the town's large blue flag beach was thus a novelty. Most of the town — and all its weekenders — have seemingly turned out by the time we arrive but the tide is out and there is plenty of room for everyone. The sea is pleasantly warm and we enjoy a refreshing dip before returning to our blanket for a picnic, and game of frisbee (Mum and Dad) or a siesta (me).

Another experience that challenges my expectations of Barmouth is a visit to Coes Faen Spa Lodge for dinner. A hotel and spa located across the road from the aforementioned Clock House, Coes Faen also serves dinner four nights per week. "It's Tuscan fare with local flare," the owner, Richard Parry-Jones, confides while we relax with a pre-dinner drink in the 'snug' living room. I am impressed by the gin collection, opting in the end for a G&T made with local Dyfi Pollination Gin (replete with botanicals foraged from the Dyfi biosphere). Served with a garnish of crushed mint, juniper berries and lime, it is unusual and delicious. After we move to our table, I enjoy the lobster linguine and beautifully cooked lemon sole. We take a walk through the property's beautiful grounds before dessert, enjoying still more views of Barmouth Bridge and the estuary. Pudding for me is a rich chocolate tart served with mascarpone, ginger and oranges.

On my final day in Barmouth, before I make the picturesque train journey back to London, we pay a visit to the Blue Lake. Located near Fairbourne, on the opposite side of the estuary (you can walk or take the train across Barmouth Bridge, but if you're driving, you'll need to go the long way round, via the Penmaenpool Toll Bridge), this erstwhile slate quarry turned wild swimming spot isn't well-signposted. Look for Fordd Panteinion, a small road that forks left off the main road south of Fairbourne, where you can park. Don't follow the Welsh Coastal path signs, but instead head to the abandoned quarry. It's a bit of a climb, but we soon arrive at the small, vibrantly coloured pool. The sun has finally gone in when we get there and the lake is not its famed sapphire hue, but looks just as beautiful in deep teal. The water is cold, but my mum, brave as always, goes for a swim. The rest of us stick to spectating. And dreaming of Clogau gold.

If I've piqued your interest in Barmouth and the Mawddach, you may enjoy my dad's book, Marians on the Mawddach, which celebrates the area, including his West Midlands school's history with this particularly lovely part of the world.