The colorful mystery mosaics on a Lenox Hill block

Sometimes the most ordinary buildings hold charming surprises. Take 239 East 73rd Street, for example.

It’s a well-kept but unremarkable tenement-style walkup, similar to so many that line the low-rise pockets of the Upper East Side’s Lenox Hill neighborhood.

But someone over the years with a playful sensibility decided to liven up the nondescript facade with a couple of colorful mosaics: one of an owl, the other of a rooster.

A yearning for country life? A whimsical representation of daytime and night? Perhaps the reason for the mosaics is lost to the ages. But they remain on the streetscape, delighting sharp-eyed passersby.