Some ephemera enthusiasts focus only on (varied themes) postcards - not a genre that appeals to me unless it's a moonlit night scene on linen, in which cave GIMME.  Here are some varieties - lake, lake with boat, the sea, a touchingly banal Main Street, Black Mountain NC.

But this last one here's my favorite night scene, a Pittsburgh steel mill, of all things. Sadly, it's undated.  I LOVE this card.