The 長 is the kun'yomi reading, which comes from 長い. The 崎 part is the same reading that you learned with the kanji (though also kun'yomi). Combine those together and you have ながさき. Sound familiar? It should. This is the city of Nagasaki, one of the cities in which the A-bombs fell.
I bought some Nagasaki sponge cake for you as a souvenir.