Trearddur Bay is easy to enjoy well, a proper family beach with a quieter cove, Porth Diana, around the headland.
CHECK FIRST · SAFETY
Do not assume lifeguard cover. The RNLI station is a lifeboat station, not a beach lifeguard service. Check current beach safety information and on-site notices before entering the water.
Time needed
Half-day beach · full day with Porth Diana
Best time
Summer for full facilities
Opening, entry & booking
Open access · free · no booking required
Access & difficulty
Flat sandy beach and promenade · easy underfoot
Parking & start point
Three car parks: Lôn Isallt, Lôn St Ffraid, Fron Tywyn
Getting there
Holy Island, ~2 miles south of Holyhead · buses 4 and 23
Toilets, food & facilities
Beach toilets, including accessible · Trearddur Bay Hotel
Dogs
Southern section restricted 1 May–30 Sep
Plan with confidence.Detailed information on arrival, access, facilities, restrictions and local conditions.
Opening, entry & booking
Open access, free entry and no booking required.
Parking, start point & arrival
Where
Three Isle of Anglesey County Council pay-and-display car parks, all adjacent to the main beach: Lôn Isallt, Lôn St Ffraid and Fron Tywyn.
Charges
Pay-and-display, set by the council and reviewed periodically. Go by the on-site tariff board rather than any figure quoted elsewhere; IACC Highways (01248 750057) can confirm in advance.
Postcode
LL65 2YU for satnav, but this covers a wide area, so follow signs for the beach once you’re close.
Busy window
Arrive early on sunny weekends.
Public transport & car-free access
Routes
Route 4 (Bangor–Llangefni–Valley–Holyhead, Arriva) stops at the beach car park itself. Route 23 (Holyhead–Trearddur–Rhoscolyn) also serves the village.
Timetables
Frequency and journey time vary. Check the current service before travelling.
Toilets, food & facilities
Toilets
At the beach, including accessible toilets.
Food & drink
Trearddur Bay Hotel, on the bay.
Accessibility & terrain
Main beach
Flat sand with a level promenade behind it.
Toilets
Accessible toilets are available at the beach.
Porth Diana & Porth Castell
No access assessment is published for the two smaller coves, and neither is reached from the main beach car parks. Plan for uneven ground.
Dogs & restrictions
1 May–30 Sep
Dogs banned from the southern section of the beach, in front of the car park.
Year-round
Leads required on the promenade at all times. The northern section of the beach is dog-friendly year-round.
Safety, weather & local conditions
Bathing zone
The main beach has a buoyed bathing zone.
Water quality
Rated good by Natural Resources Wales in 2025.
Lifeguard cover
See Check first · Safety, above.
PLACE-SPECIFIC DETAILS
Diving & watersports
Porth Diana
A second sandy cove reached via Ravenspoint Road, separate from the main beach car parks. Used for diving, snorkelling and, every August, sailing club dinghies.
Porth Castell
The smallest of the three coves, about 5 metres deep at high tide, with a gully to the left of the entry leading to deeper water toward Ravenspoint. Check tide times for Trearddur Bay before diving: Met Office, reading the Trearddur Bay station 0.8 miles away.
Main beach dive site
Divers may be asked to use an SMB during busy periods.
The sailing club
Season
Racing is a summer fixture here. Check tbsc.org for the current programme before planning a visit around it.
The RNLI station
Operating
The inshore lifeboat station on the bay has been operational since 1967.
Not a lifeguard service
This is a lifeboat station, not a beach lifeguard service. See Check first · Safety, above.
What to bring
Windproof layer
Swimwear & towel
Water
Snacks
Cash or card for parking
Dog lead if needed
Saved tide times if diving
Camera or binoculars
This isn’t a hidden beach.
Trearddur Bay is a proper resort village on Holy Island’s west coast: a working lifeboat station, a sailing club that’s raced every August since 1919, a hotel on the front. Not remote. Not wild. A sandy bay that knows what it’s for.
Round the headland, Porth Diana and Porth Castell are quieter, a second and third cove most day visitors never reach.
The bay is the start of it, not all of it.
Should this shape your day?
A proper family beach with a working village behind it.
Good fit for
families wanting a full day at the beach
divers and snorkellers (Porth Diana, Porth Castell)
walkers connecting to the coast path toward South Stack
visitors wanting a beach base for Holy Island
car-free visitors: bus routes run from Holyhead
Think twice if
you want solitude in summer
you’re driving in peak season without an early start
you want a remote or wild beach
your dog is with you in summer and needs the whole beach
you expect lifeguard cover, because the RNLI station is a lifeboat station, not a beach patrol
Arrive early, walk the circuit from the hotel to Porth Diana and back, then spend the afternoon on the main beach.
The Trearddur Bay Hotel anchors the front: pub, restaurant and garden bar over the bay.
One bay, seven scenes.
See the shape of the visit before you commit to it.
01 Arrival
Park at Lôn Isallt, Lôn St Ffraid or Fron Tywyn.
02 Main beach
Sand, rockpools, a buoyed bathing zone.
03 Underfoot
Tywyn y Capel: a cemetery beneath the sand.
04 RNLI station
On watch over the bay since 1967.
05 The headland
The path around to Porth Diana.
06 Porth Castell
The smallest cove, so check the tide.
07 Back to the village
The hotel, the sailing club, journey’s end.
Seen along the way.
Sand, rock and the coves around the headland: the visit before you make it.
Porth Diana: the second cove around the headlandPorth Castell: the smallest cove, a shore-dive site at high tideThe RNLI inshore lifeboat station, on the bay since 1967Towyn y Capel: the beach with a cemetery beneath itSaint Ffraid’s Millennium Cross, above the beach
The parts people remember
The main sand is what the village is built around. The rest of Trearddur only shows itself if you walk past it.
01
The beach doesn’t make you wait
No walk-in, no tide window. Park at any of the three car parks and the whole bay is already in front of you.
02
A village that still works
The hotel on the front, the lifeboat shed on the slipway, and Trearddur feels lived-in, not arranged for visitors.
03
Round the headland, it empties out
A short walk around the headland and Porth Diana keeps its own quiet: one bay from where you park, two more if you keep going.
04
A cove that needs the tide
Porth Castell is barely a beach at low water. Come back when the tide’s in and it’s a different place.
05
The cross on the dune line
A stone Celtic cross stands on the rise behind the sand, above the shoreline rather than on it.
Trearddur is bigger than its first beach. That’s what people come back to.
Bay Archive
Old stories, carefully told.
Three field notes on what this bay means: a cemetery under the sand, a club that’s raced since 1919, and a name mistaken for Arthur’s.
Some of this is documented history. One entry is a documented misreading, and worth telling honestly as one.
Field notes
Three entries. Open one to read the note.
History & memory Fact
Tywyn y Capel
Field note I · filed under the beach itself
What you cross on the way to the water is centuries older than the resort around it.
What is known
An early medieval burial ground, Tywyn y Capel, sits at the centre of the main beach. It was excavated in 1997 and again in 2002–03, and was known to antiquarians as far back as 1781, when the naturalist Thomas Pennant documented it.
What the names remember
The dunes here were once called Towyn y Capel, and the bay itself Porth y Capel: the dune, and the bay, of the chapel. The chapel these names remember has never been located.
What to notice there
Nothing marks the site on the ground: the excavated area was reburied.Excavation findings · records unclear
Working coast Fact
The club that races in August
Field note II · filed under the working bay
A hundred years on, the club still keeps to the calendar it started with.
What is known
Trearddur Bay Sailing Club held its founding meeting on 23 August 1919, with 17 people attending. The first regatta had six boats, ranging from 13 to 19 feet. A shotgun served as the starting signal until a flagpole was erected in 1922.
What’s said now
The club’s racing tradition continues, but programmes change from year to year. Check the club before planning a visit around a particular weekend.
What to notice there
Three of the original Insect-class dinghies (Hornet, Midge and Ant) are recorded as still in existence. Look for the fleet on the water if you’re here in August.
Folklore Folklore
Trearddur, or Trefarthur?
Field note III · filed under the misread name
One old spelling of this name has been mistaken for a king’s, and it isn’t.
What is known
The village name was first recorded as “Trearddur” in 1749; earlier documents show the variants Treffyarddr, Trefarthur and Tre Iarthur. The name derives from the settlement of Iarddur, a medieval figure.
What tradition says
The “Trefarthur” variant has led some to connect the name to King Arthur. This is a documented folk etymology; the connection is a misreading, not a real one.
What to notice there
The bay itself carried an older name too: Porth y Capel, the bay of the chapel, a name that outlasted the building it remembered.
Don’t let the day end at one beach.
Four stops that turn one bay into a Holy Island day.
