Llangollen is a sleepy little town on the River Dee, famous in past times for having one of the "Seven Wonders of Wales" - its medieval bridge.
Today the town is more famous for its annual International Musical Eisteddfod, which attracts competitors from all over the world.
Incidentally, the Welsh "ll" is pronounced by putting your tongue in the position to say "L" and then simply blowing instead of saying anything. (If you produce a copious spray of spit, you have probably got it right!) Making this sound in the middle of a word is left as an exercise for the reader.
While not strictly in Llangollen, the Pontcysyllte Aqueduct is sufficiently close that this is the best place for our film about it.