Rhyl, seaside town, Denbighshire (Sir Ddinbych) county, historic county of Flintshire (Sir Fflint), northern Wales. It lies on the coast of the Irish Sea at the mouth of the River Clwyd. The city is mostly a vacation hotel, with broad sandy beaches and superb rail and road links with Lancashire along with also the English Midlands. Its promenade stretches for 3 miles (5 kilometers ), with a domed...