If you've gone through all the lessons preceding this one, you will be thoroughly drilled on the difference between "the ... is" an "this ..." where ... stands for any noun. " This coast" in Arabic requires the definite article for coast. It means "this is a coast" without the definite article "al", ...أل
Another possibility is "this is a very scenic coast"; I wish you had read (and taken to heart) my detailed comments about "pretty", quoting to you two very reputable dictionaries, the Oxford English-Arabic and the Hans Wehr Arabic-English. "Pretty" is close to the worst choice as a default for "jameel"