Which are the most famous landmark in the area? (Mrs Smith)

Which are the most famous landmark in the area? said Mrs. Smith. Mrs. Smith asked which were the most landmark in the area.

We make some changes when we make direct speech into indirect. If the first part is in past tense we turn the second part into past tense, too. If the first part is in present we dont change tense in the second part.  Interrogative sentence is turned into affirmative. We change said into asked in interrogative.    

 Mrs. Smith says Which are the most famous landmark in the area? said Mrs. Smith. Mrs. Smith asks which are the most famous landmark in the area.