A must-see, I believe it is the home of largest Roman temple in the world. And the site was much larger then I had anticipated (actually home to over three temples) and was a stop along an ancient trade route. Plus, in the summer they have a festival here with world-renowned entertainers! It is amazing, from Dizzy Gilespie (yes, DIZZY!) to Warda Al Jazairia.I took a tour from my hotel that included Baalbeck, Ksara Winery, and Anjar (an entire ancient city!). I went through Nakal Sightseeing Tours, as recommended by my hotel. The tour guide was well informed and multilingual—wonderful! Her name was Madilyn, and she was great! See www.nakhal.com. the price was US$60 and included lunch, an all-day tour (guided), transportation, and hotel drop-off and pick-up. Call 961 1 382 444.
One thing I really enjoyed about the archaeological sites throughout Lebanon: they let you walk around in them. Other places, they would allow you to view it at a distance, and you can never walk all through them (even Stonehenge is blocked off).
Website: http://www.baalbeck.org.lb