The garden of Beirut's National Museum... I'm sure that many haven't thought of visiting this underrated location, but here are 2 important attractions that worth checking out:
1- The remains of a Byzantine basilica, just beside the Roman columns, was also discovered in downtown Beirut during archaeological excavations, and was later relocated to its current location. The mosaic floor of the basilica depicts beautiful icons of animals and crosses, and the basilica's aps can still be seen on site.
2- The well preserved Roman Columns with their beautiful frieze, were part of a Roman forum that was probably discovered in Nejmeh Square (check last picture).