Tresaith is a great family beach, it is safe (lifeguarded July and August, from 11am till 6pm), sandy and has all the necessary amenities nearby (beach shop, cafe, pub, toilets - with wheelchair access).
At high tide, the beach is not large, but at low tide there is quite a large swathe of sand. The River Saith (the origin of Tresaith) emerges over the cliff tops on the northern end of the beach as an impressive waterfall - a freshwater shower for those wanting to wash salt and sand away!
Situated between the amenity less, but spectacular, Penbryn beach (owned by the National Trust) and the two beaches of Aberporth, it is probably the best choice for families. Its popularity in the Summer means that for most of the day, there is no available parking. The nearest car park is a field at the top of the village, but it does necessitate a steep climb at the end of a perfect day on the beach!
For experienced surfers, Tresaith is probably not the best beach, as it is relatively protected from South West winds. However, for beginners, it is an ideal choice because it provides an easy introduction to the sport.
However, it is an active boating base with a slipway for visitors and an active sailing club - Tresaith Mariners.
The Coastal Path provides an easy walk to Aberporth (about two miles away) There is a fairly steep climb up to it, but the going is relatively easy after that. For nature watchers, there are the ever present Bay Dolphins and seals. For trainspotters, there are an abundance of pre-nationalisation railway carriages to take note of - converted now into holiday chalets! You can stay in a very nice example of a clifftop railway carriage here..
In the other direction, it is possible to walk to Penbryn when the tide is out, but beware the incoming tide for each year holidaymakers have to be rescued because they hadn't read their tide tables!
There are two "eateries" - a Cabin next door to the Siop y Traeth (Beach shop) with tables on a terrace (but no enclosed space) It has a traditional kiosk menu - Fish & Chips/Beef Burgers/Bacon Baps that type of thing. The Ship Inn has a terrace with views to die for.