Your best ways to get to Croatia/Slovenia

You don't indicate where you're flying from (in the USA?), so where are your options for direct flights to Europe?

When I went, I flew Seattle -> Heathrow -> Zagreb. I'm not sure why you're finding it challenging to get there and back. I am sure there are many options that involve just one connection, assuming you can fly direct from your local airport to some European gateway.

EDIT: I see now you are in Virginia. Assuming you can fly from DC, you should have no problem.

For Slovenia, short of flying into Ljubljana, Venice is the best option by far. While there are no Venice to Ljubljana flights or direct trains at the moment, there are direct buses and shuttles from the airport into Ljubljana, the distance is only about 240 km (150 miles).

There are no direct flights from Budapest to Ljubljana either. It's a bit more complicated there, but it's probably best to take a bus to Ljubljana or the train or bus to Zagreb. The train to Ljubljana simply takes too long.

Besides flying into Venice or Budapest, you could look into flying to Vienna or Munich, both directly connected to Ljubljana via plane, train, bus and shuttle. Some other airports that are not too far from Slovenia are Trieste just across the border in Italy, and Milan, which is further away, but you can get to Venice or Trieste by high-speed train and then again to Slovenia by bus or shuttle.

I've flown to Croatia four times from DC. It was not cheap, but I am by no means rich. We probably paid no more than 1400 each on any occasion, and they were often open-jaw flights, with only one brief stop (Germany is my current favorite place to layover). I don't do the change carriers thing--I only have 10 days for vacation, so I maximize my time on the flight portion. I also don't want the stress of changing airports, dealing with luggage, etc.

I've flown into Venice a few times to start a trip in Slovenia. You can get to Ljubljana as mentioned above by bus or transfer - look into DRD or GoOpti. FlixBus may have cheaper direct buses but perhaps not from the airport. If you want to add some time in Trieste, you can detour through there from Venice too (you can get from Venice to Ljubljana almost entirely by train via Trieste but you must connect from Trieste Centrale to Villa Opicina (or Sezana) near Trieste by bus...or take a train to Trieste, bus from there to Ljubljana.

On another trip, I flew into Munich and trained down through Salzburg and Graz to Maribor to explore eastern Slovenia a little - also gave me the opportunity to stop in Austria. In that case, the Munich flight was a lot cheaper than flying directly to Slovenia, which would have been faster, but the cost savings in effect paid for the extra days spend in Austria.

On trips ending in Croatia, I've flown out of Zagreb and Split back to western Europe before flying home. It helps if you don't mind spending a few nights in Paris or Amsterdam or something at the end and have the time. Sometimes it's possible to connect in the western European city on the same day, depending on your flight times, but some find that too risky. (I've done it but not from Croatia.)

I've checked all of these options for each trip - one isn't always the best. Depends in large part on the flight schedules at the time. For example, one year I had a frequent flyer ticket to Amsterdam and needed to get to Ljubljana. My incoming flight from the US to Amsterdam arrived just over an hour before a direct Adria flight to Ljubljana. I probably would have made it (as it turned out) but the layover was just too tight to risk it, so I took a Venice flight an hour later. Had the Adria flight left an hour later, I surely would have taken that instead and skipped Venice.

In 2015 I visited Germany before the Balkans. My connection was via bus from Munich to Ljubljana. From Dulles, Munich is often a relatively cheap destination.

For Munich-Ljubljana, the travel time by bus is about 5 hours. I'm not sure all the schedules are loaded for 2018, but you can take a look at GoEuro to see what's there. I'm sure I don't have to tell you that it would be risky to wait until your travel date to buy that bus ticket.

The fastest/easiest connection between Slovenia and Croatia is by train or bus between the capital cities, but there's also bus service between Ljubljana and Rovinj.

My return to the US was on a United frequent-flyer ticket from Zagreb with just one stop in either Frankfurt or Amsterdam. It wasn't a bad routing at all, but the flight out of Zagreb was early enough that I opted to stay out near the airport the night before; I found an inexpensive place that would provide free shuttle service. I used the airport bus to get me to the airport on the eve of my flight and was able to walk to my lodgings. I was just a bit nervous about relying on that airport bus for a really early flight.

Every time I've looked, it has seemed that Zagreb is a considerably easier access point by air than Ljubljana. If you want to start or end in Ljubljana, I'm betting that you'll find it cheaper to fly into or out of Munich and use the bus rather than traveling via Venice. Depending on how the schedules fit together, the Munich gateway may also be faster.

Sorry, I'll be flying from one of the Washington DC airports. I've flown out of all three - depending on which one I can get the best deal from. I might even fly from Phil/NYC if it's a better route in terms of duration and price.

It's not necessarily challenging to get there. The challenge is to do it at a reasonable cost and duration. I don't like to spend more time en route than necessary. My last three round trips to Paris have been under $500 and about ten to eleven hours each way, including a stop in Iceland. The thought of paying better than three times that for a 20 hour duration trip makes me think there's got to be a better way.

Andrew and acraven, Thanks very much. Those are exactly the kinds of answers I'm hoping for. When I start planning, the first job is to explore all the options. Then I balance them against each other and pick what works best for this trip. I'm sure I wouldn't have considered a bus from Munich without asking.

I certainly have not done any 20 hour itineraries, but I have to pay for convenience with limited time.
No way will you get in and out of the country for 500, but with time and flexibility you can get under 1000--it just depends on your timeline and what parts of the country you plan to visit. Look at Kayak and start tracking. I am considering returning next year and so I took a gander, and I am seeing some good fares round-trip to Zagreb in late May.

As you check train schedules to Ljubljana, look for next week or later to catch any changes that may happen with the biggest annual schedule change on Dec. 10. In the case of Venice-Ljubljana, the new schedules incorporate a bus transfer from Trieste that's faster than the route via Villach that was prominent in the past few years. (There are also direct DRD buses or GoOpti shared shuttle vans from Venice to Ljubljana, Flixbus from Trieste, or high season ferries from Venice to Istria.) Trains from Budapest will still take 8 hours next year and from Vienna 6 hours.

Laura, I had heard (from you?) that there might actually be a direct train from Venice to Ljubljana again at some point. That would be super sweet.

But I'm not sure how a new bus connection from Trieste to Ljubljana will help much, given that there are already such buses? There are several trains from Venice to Trieste a day now so it's not that difficult to pick one that lines up with the existing bus schedules e.g. Flixbus. It makes more sense to go via Trieste if you can spend at least a few hours there exploring - then a longer layover may make more sense. Otherwise, DRD or GoOpti direct from the airport is faster, easier, and not more expensive if the goal is simply to get between Venice airport and Ljubljana. (Figure: bus from Macro Polo airport to Mestre station; train to Trieste; bus to Ljubljana vs. airport pick-up direct to Ljubljana.)

The direct trains are still in the cards, but not until spring/summer 2018 at the earliest. A benefit to the bus connection in the DB timetables is that the entire journey can be done on one (train) ticket.

Typically, I'll arrive by air and stay in one place for a couple of days before moving on. I'll probably do something open jaw. So if I fly into Munich, for example, I'll probably fly out of another city (Budapest, Milan, Venice, Vienna). As I'm looking at the options, I'll hop on the one that makes the most sense.

I don't mind a bus from Munich, but at five hours I'd weigh it against a flight; I have a rule of thumb of four hour travel legs to the maximum extent possible. I do everything now with only a small shoulder bag, partly to stay within even the strictest carry on limits and partly because I prefer traveling really light.

As far as costs go, I'm finding the best prices are about $800 round trip to the major European cities right now from DC. Unless next year is different than the last two years, I think I can find lower in the two to three month out time frame. Once in Europe, flying a European carrier will probably work best but I'd train or bus if it's under four hours and costs less. I don't like to start driving until I'm in the area I where I actually need a car - then drop the car as soon as I can again rely on other transportation.