I would suggest staying within Beirut - see Zeitounay Bay, the Corniche, maybe lunch in Hamra, tour the downtown (Martyrs Square, churches, mosques) can go to the National Museum, have a sundowner on a rooftop bar (try Iris downtown, or the Movenpick hotel if on the Corniche) I would not recommend going out to the Jeita Grotto or Kaslik if you only have a day
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