For scenery, mountains and water sports, you can’t go wrong with the Alps. Aim for Switzerland & Austria, and the bits that border them.

Slovenia is gorgeous, particularly the mountains in the north west. I spend a few days in Bovec, and it’s a great base for all the things you want. Hiking, canyoning, climbing etc. Lake Bled, nearby is spectacular. And Ljubljana is a nice capital.

Allow yourself at least a couple of days to get there if you’re starting from Ireland, and a couple of days to get back. You could easily spend 5 days in/ around Bovec, and a couple of days in Ljubljana. That leaves you with maybe 3 or 4 extra days to spend somewhere in Italy, Austria or Switzerland? Or a trip from Ljubljana to the Croatian coast?

You might want to read these pages on Seat61 for guidance.

Dublin - London https://www.seat61.com/train-and-ferry-to-dublin.htm

London - Switzerland https://www.seat61.com/Switzerland.htm

London - Slovenia https://www.seat61.com/Slovenia.htm

I’d advise a route via Brussels and Germany, rather than going via France. That’s because there are more reservation fees with the Interrail pass on the route via France. You could take daytime trains, or even the sleeper from Brussels to Vienna.

Good info on reservation fees here; https://www.seat61.com/interrail-and-eurail-reservations.htm

Thanks so much for the reply,  I plan on flying from Ireland to my start point and fly home from the end destination to give us more time to see more places and do things . Is there anywhere you can find itinerarys that people have used as I wouldn't know where to start  , you can't fly direct to Slovenia from Ireland so would you suggest I start in Switzerland or Austria. 

You could fly into Basel or Milan with Ryanair or Geneva, Zurich with Swiss or Aer Lingus.

If you fly into Milan travel along Lake Como afterwards and take the splendid Bernina route in Switzerland. More : https://www.seat61.com/trains-and-routes/bernina-express.htm

You could leave from Salzburg or Vienna. The other way around is possible of course.

Split and Zagreb are also possible airports.

Thanks , how many nights would you suggest in each destination,  would you get away with 1 day in some places I'm like a rabbit in the headlights really 

I wouldn't spend less than 2 nights (so 1 full day) in most places. Better to stay longer and make day trips : for example Ljubljana and Bled are so close that it makes more sense to stay in one and visit both.

For example if you land in Milan at midday you could easily make it to Varenna/Lake Como area. Relax in the afternoon/evening and the next day visit the surrounding villages taking boats. The following morning train to Tirano and train to St. Moritz*. Visit the town if you want but I'd recommend staying in a cuter village in the valley (Zuoz, Zernez,...).

Of course expect most places to be busy in summer but as soon as you hike a bit you'll be pretty much alone.

*some regional trains in summer have open-air carriages ! It's a cool experience but don't forget to bring a jacket. Those trains will have an AW symbol on SBB app. https://www.rhb.ch/en/world-of-railway-experiences/railway-experiences/open-panoramic-cars

I was thinking of something like this for example 

Fly to basel and get the trian to chur stay overnight then get the bernina express to milan 

2 nights in milan going to lake como and other things ?

Milan to venice stopping off in lake garda on route and then stay in venice for 2 nights or would it be cheaper to stay in a nearby village ?

Venice on to Ljubljana and stay 2 nights 

Ljubljana to budapest stay overnight 

Budapest to vienna stay 2 nights , again would it be cheaper to stay in a nearby town ?

Vienna to venice and fly home 

I chose venice to fly home as it has direct flights to my city 

Does that sound feasible in 2 weeks or is it madness and also am I missing out on any hidden gems along that route ?

Thanks for all the advice 

The Bernina Express has 2 parts : reservation-free carriages at the front (pull-down windows) or panorama carriages with a 25 CHF mandatory reservation.

I wouldn't stay in Milan : not the best Italian city and it'll be very hot in summer. Instead find something not too expensive on the eastern side of Lake Como.

I wouldn't spend only a night to Budapest. 

Mmm you'll lose a full day travelling to Venice and your time is already limited. I'd choose a more expensive flight over that. Consider leaving from Budapest too :

- Ljubljana - Vienna - Budapest

Btw between Venice and Ljubljana your options are quite limited : only 3 trains a day between Trieste and Ljubljana. There are more trains via Gorizia : take a bus to Nova Gorica on the Slovenian side (1-2€) and then a train into the country.

In the end my itinerary would be :

- Chur 1 night

- Lake Como 2 nights

- Venice 2 nights (Mestre on the mainland is cheaper but then you have to take a bus/tram/train to the city)

- Ljubljana 3 nights

- Vienna 3 nights

- Budapest 2-3 nights

Where do you live in Ireland ? Ryanair flies to Cork only until March. If Venice must be at the end I'd remove at least Budapest and maybe take the Milan - Vienna night train to save time.

Appreciate all this thanks,  I'm from Cork so have a few options but I don't mind flying put of Dublin as its on 2.5 hours up the road which is why I was going to fly to basel from there  , ya I'm not sure if I'd like budapest as we aren't into museums and the likes is there much to do there ? What would you suggest doing in Ljubljana and Vienna ? Are hostels safe in all these places as I'd imagine hotels would be extortionate. 

Also it will probably be July when we travel 

I haven’t visited those places so can’t really tell. There are often private rooms in hostels, you’d have to stay in those as children under 18 y.o. are rarely (never) allowed in dorms.

Ryanair doesn’t fly between Cork and Venice after March (I don’t know why). It does fly to Milan (Bergamo airport, far from the center) but quite expensive and at awful hours...

Swiss is flying between Cork and Zurich and it would be an interesting option. Doesn’t look like too expensive on some dates. For example :

• Monday 15th July : Cork - Zurich 19:45 - 22:50 77€
• Monday 29th July : Vienna - Frankfurt - Cork 11:20 - 16:30 120€

Venice - if you’re looking for accommodation, I really recommend Meninger Hostel (it’s part of a big chain). Brand new build, so really clean and lots of facilities. It has an entrance that’s pretty much backs on to the platform at Mestre station. Much cheaper and better accommodation than staying in Venice, and the trains are very frequent and quick. And included in your continuous pass.

There’s also a Staycity Apartment, Campanile hotel and Leonardo Hotel in the same development.

Venice is a great city for people who ‘don’t like museums’ the city itself is the attraction. Take a vaporetto down the Grand Canal (expensive, but worth it once). Just avoid the busiest bits around St Marks Square and Rialto. If you walk 5-10 minutes away from there, it’s laid-back, more charming and cheaper places to eat etc.

Vienna - I didn’t find it to be as worth visiting - especially if you’re not into museums, opera etc. Budapest was cool. Brno it the Czech Republic  and Bratislava, Slovenia were also great. Small enough to walk around easily, plenty of interesting sights.

I wouldn’t worry about safety of hostels in that part of the world at all. As @thibcabe says, you might not be able to use a dorm room with under 18 in some countries. Better check that out. Also check Airbnb for accommodation.

Ljubljana - yeah I loved the city itself, but I think you might prefer to stay up near the mountains. Bled, Bovec or somewhere like that, and visit Ljubljana for a day trip, or a half day while changing trains.