Speaking of travel, have you ever visited New York City?
Literal
Travel [quotative-と] speaking-of, New York City [object-を] visited [experience-ことはありますか]?
~と言えば (speaking of) shifts to a related topic, then ~たことがある opens a question about past experience. 訪ねる (to visit a person or place) is slightly more formal than 行く (to go). The は in ことは adds slight emphasis on the experience itself: 'as for visiting, have you...?'