They had it all

You can watch true love blossom in a steamy double feature, 1946’s “The Big Sleep” and 1948’s “Key Largo,” starring Humphrey Bogart and Lauren Bacall. The couple, who married the year before “The Big Sleep” premiered, made four films together before Bogart died in 1957.

7 p.m., TCM

Lost at sea

The four-part series “Safe Harbour” finds Australians on a yachting holiday at odds with asylum seekers after a mysterious incident leaves behind several dead refugees. Phoebe Tonkin, best known stateside for “The Vampire Diaries,” is among those on the not-so-calm waters.

Now streaming on Hulu

It’s Greek to me

In “Ancient Invisible Cities,” Prof. Darius Arya takes you places tourists rarely see with the help of in-the-know locals and 3-D technology. First port: Athens, where the most exciting stops are beyond the shadows of the Acropolis. The other stops on the schedule are Cairo and Istanbul. More, please.

8 p.m., TPT, Ch. 2

Neal Justin