Piran

TRIESTE ... it's no contest. So, so much history in Trieste and a whole lot of architectural delights to back that up.

Really enjoyed visiting Trieste!

There is most certainly more history in Trieste, but I found Piran (tiny compared to Trieste) utterly charming and fun. In rainy weather I'd prefer Trieste for sure, but I found it more interesting than appealing.

I second what Andrew said. I haven't been to Piran but would love to go.

Trieste appeals to me more for things to see and do. Piran was fabulous for somewhere memorable just to be.

I loved Piran when I went but you can also see pretty much everything the town has to offer in about an afternoon. That said, if all you want to do is relax in a charming environment, could easily spend 2 days there.

We’ve never been to Trieste but we spent a day in Piran on a cruise that stopped in Koper. It was a pleasant day and I would agree with kevlar, above. We don’t factor in much relax time on our travels so I see places in a different light perhaps. Safe travels.

"For a beautiful 2 days on the coast" I'd pick Piran. Really enjoyed it there. Treiste was, as others said, interesting more than 'beautiful'. Here are my photos of both towns: https://andiamo.zenfolio.com/p569846134 - images #30-55 are Trieste.
https://andiamo.zenfolio.com/p121432302 - This gallery is all Piran

Liking the Udine photos, yet another smaller Italian city that gets overlooked.

Thank you all for the comments and pictures! Thought we’d relax with a lovely view before we started our Adriatic tour! Appreciate it !

Piran is my happy place. If you’re lucky you’ll be there for a flea market.

And we love Vienna! Thank you!!