Al Mina Archeological site, Tyre

Dating to the 3rd millennium BC, these atmospheric ruins cover a large area leading down to an ancient submerged harbours. Highlights include a street paved with geometrical Roman and Byzantine mosaics, on each side of which are rows of large columns. Look out also for the unusually large public Roman bathouse from the 2nd or 3rd century AD and a 4th-century rectangulae arena that would have held up to 2000 spectators, perhaps to watch some sort of ancient water sport.