Iceland - South Coast or Golden Circle?

Clarifying questions: you have three nights in Iceland total? You're staying in Reykjavik? You want to do one day tour on one of your two full days (because three nights is only two days)? If the answers are yes, yes, and yes, then I would pick Golden Circle as it hits the iconic Iceland sites. It will be cold and potentially snowy/icy in several places on the loop so dress for the weather.

I'm going to disagree. With three nights there, that gives you two full days, which is more than enough time to see the highlights of the South Coast. While you cannot see everything, two days allows you to explore the waterfalls, black sand beaches, and glacier lagoons without feeling too terribly rushed in my opinion.

I would highly urge you to try and see it if it's at all possible. You would still have some time when you arrive to see Reykjavik.

I'm sure Mikliz will be chiming in, so I will let her respond, and she may disagree with me. Keep in mind that I have not yet been to the South Coast, although I am heading there in July. But that is what I have read from pretty much everyone so far. And our schedule to visit the South Coast would take about two days, so I don't see any reason why you couldn't do it.

Don't get me wrong, the Golden Circle is really nice and worth a visit, but I would do that if I only had one day there (that is what I did back in 2018 when I only had two nights and one day in Iceland). With two days, I think you could definitely expand your horizons.

I only had 3 days there in Aug. 2 years ago. I went on a South Coast tour one day and the Golden Circle the next day. Though both tours were fantastic, if I had to pick just one, then the South Coast was my favorite. Also did a food tour on my 1st day there, to see a bit of the city and get some history as well as taking a bit of time to go up in the church tower. The Golden Circle tour included a last stop at the Sky Lagoon. So, I packed as much as possible into my 3 days.

I would suggest doing a 2 day south coast tour. The GC is fine, but does not compare to the south coast at all, IME. If you don't want to do a 2 day tour, then I would do a day tour to the south coast and another day tour to Snaefellsness. This would actually give you the most variety, but it would be exhausting having two really long day tours back to back. So of all of this my first choice would be a tour day tour to the south coast and skip the GC.

I'd just add that spending time in Reykjavik proper is worth some of your time, it is a pretty walkable city. If you do day tours both of your days you won't have much time to do that, especially if you want to be there when things are open.

If you do day tours both of your days you won't have much time to do that, especially if you want to be there when things are open.

CL, it is my understanding that almost all of the flights from the west (i.e., the US) that arrive in KEF do so in the early morning between 6-8 an. That has been my experience on both of my trips there, and that is what I have read. That gives the traveler the perfect opportunity to spend the day in Reykjavik, just wandering through town and enjoying the sights and so on.

In fact, that's what I did on my first trip, when I only had two nights there. My flight got in around 6:30 a.m., I took the bus into Reykjavik and spent the day just wandering through town and seeing what I wanted to see. Then I spent the next full day on a Golden Circle tour and then left early the following morning.

CL, it is my understanding that almost all of the flights from the
west (i.e., the US) that arrive in KEF do so in the early morning
between 6-8 an.

That is true Mardee I myself did the same thing, but a jet lagged Reykjavik isn't the best experience in my opinion. As OP hasn't returned to clarify if this stop is on the way to or from Europe or what flight times might be, they will need to sort out the suggestions that suit their situation.

Thank you everyone.

Arriving 4/12 to Iceland at 1535 from Europe.
Depart Iceland 4/15 at 1945 for return to US.
Full day free on 4/13 and 4/14.
Ideally would enjoy time to explore town, as well as time to see Blue Lagoon (either on arrival or departure).
I appreciate all of the information.

That helps a lot! I would do the Blue Lagoon upon landing. Do that and then head into town and get dinner and wander. Do a two day south coast tour, and then you have pretty much a full day to explore Reykjavik. With an 8pm flight, you will need to be there by 5 (yes, really 3 hours is often needed here). Reykjavik is 45 minutes away, so say 4pm to leave there. That gives you a whole day to explore the city.