Pompeii and/or Herculaneum - Roman ruins

When I get back to the area a second time, I'll eagerly see Herculaneum. If one has ample time, see both--but if you have to choose, Pompeii all day. To see the scope of that city with Mt Vesuvius looming in the background was an amazing experience.

We've done both and we preferred Herculaneum. We followed the Rick Steves book on how to do it -and it was perfect - we followed his well written-out tour - it was VERY good. Don't miss the skeletons at the very end down the stairs - it is very moving. We also ate some of the best pizza we had in our 3 week in Italy on the way back to the train stain. It's on the LEFT, on the main street, as you leave Herculaneum and walk to the train station - Pizzeria Luna Caprese Sas Di Luna Michelina

I think if only one, then Pompeii. Pompeii gives a better view of Roman life in a city, different functions of the buildings, a varied array of life. Herculaneum, while I suppose better preserved, is not "that much" better preserved. It is much smaller, sort of like getting a glimpse of a couple blacks of a city, rather than an expansive view like Pompeii. Herculaneum does however more explicitly illustrate the depth of the ash covering.

I will add though, before committing to seeing both, I would do Pompeii and the Archeological Museum in Naples, before adding Herculaneum.

I have been to both, and agree that Herculaneum is best especially if you have less time to spend. It is remarkably well preserved, better than Pompeii. I highly recommend it. If you are visiting Rome, I also recommend Ostia Antica. Just a train ride away, and you can spend a full day there. Fabulous.

https://community.ricksteves.com/travel-forum/italy/herculaneum-and-pompeii-questions

I think the difference in the degree of destruction has been overstated by your sources. That is an opinion, not a Ph.D Thesis paper. There is a widespread myth that Herculaneum is better because it is smaller. (see next post) Neither city has been completely excavated. Our host, Rick, has pointed out that Pompeii MUST have had a Synagogue. But one has not yet been found, for example. Herculaneum is a hot 15 minute walk from the train station. Pompeii is right there. Since modern cities have been built, more excavation will be very difficult.

Edit after next post: Google Maps says it's 8 minutes, but New Yorkers are fast walkers. And I still couldn't do it in 8 minutes. What if you have your bags with you, as many posters here do? Google Maps also says there is a 37 meter (!) difference in elevation. When you are walking back uphill to the Cirvumvesuviana, in 90 degree F heat, it feels like a mountain! As I think I said in the linked discussion, another problem with Herc is that there's no food inside the site, only some vending machines. You cannot exit and re-enter on the same ticket. So plan your meal to match Italian restaurant lunchtimes.

https://goo.gl/maps/d6wD7KxrM3XtJG3fA

There is a FIVE site, maybe one-week (once each) ticket available, as well as Ostia Antica, and Hadrian's Villa in nearby (Rome) Tivoli to be considered as well. Your question is smart, but it's not the last word. (Irony, not insulting you!) Not to mention the oracles' caves near Naples, and a lot more. Heck, there's a great Roman ruin under Cologne, Germany, open to the public.

Herculaneum is more like a 5 minutes' walk from Ercolano Scavi station, so don't let that influence your choice.
Even though I visited Pompeii much more recently than Herculaneum, the latter left a more vivid memory. Not sure why since they are both impressive, but perhaps because there was almost nobody there when we visited.
Also, Herculaneum can be done in 1/2 day from Naples, whereas Pompeii deserves the best part of a day.