Swallow Falls, also known as Rhaeadr Ewynnol in Welsh, is a 42m high waterfall near Betws-y-Coed in Snowdonia.
You can park at the Swallow Falls Hotel or along the roadside, pay a £2 entrance fee, and take a short walk to two viewing platforms to see the upper and lower sections of the waterfall. However if you prefer to make an adventure out of it my favourite way to see the falls is to walk from Betws-y-coed (see seperate listing "swallow falls walk")
It's a quick stop that may not be worth the entry fee for some, but offers a picturesque view of the falls.