Europa in winter, by train, as a 25 year old

Hello everyone!

I am planning on travelling to the south of Europe for about two weeks in december, as I have a vacation then. I never travelled solo in my life so I want to take this opportunity while I still have it, as I will start my first job in January.
I am a active 25 year old male who wants to make the most of a trip within Europe, coming from the Netherlands myself. However, I find it difficult to plan a trip, as there are some limitations in place:

- I want, if possible, to travel to less crowded places and be able to see a lot of nature and make hikes
- I am planning on travelling by train, using an Interrail ticket (I recently flew to Vietnam and took lots of flights there, so I've had enough of airports for now. Of course, if I realize my plan won't work, I'll consider other continents - I just prefer to stay in Europe.)
- I am aiming on visiting the south of Europe to try and reach places where the temperatures are above 5 degrees Celcius, and if possible, 10 degrees.
- I am okay with taking some stops on the road to my destination, as I do realize travelling by train from the Netherlands will take some time. I think I will buy a 5- or 7- day Interrail ticket and see multiple places as I travel.

I think my best options would be Spain, Greece, Portugal or Italy considering temperatures. Do any of you have recommendations for travelling here in the winter? My focus is not on the bigger cities, rather on smaller places. Thanks!

Temperature shouldn't be a problem. I've frequently travelled to Andalucia (southern Spain) between December and March, and temperatures tend to be between 10 and 20 degrees, frequently sunny (even t-shirt weather during the afternoon, though cold in the mornings and at night) - though of course things are never completely certain where the weather is concerned.

Getting there should be pretty straight-forward: great high speed connections to Paris (just annoying to transfer to a different station there for your onward travels), Madrid/Barcelona, and then within Spain to any medium-sized city you want (e.g. Sevilla) and onward from there. Maybe busses for the last leg. (I have no experience with Italy or Greece, so won't comment on those. I imagine getting there by train should be doable, but would mostly just take longer.)

The combination of hiking in nature and being limited by public transport is a difficult one. Is it an option to rent a car to get around when there? If so, Sierra de Grazalema would probably be my first recommendation: lovely small villages, pretty quiet since it's the low season, and lots of worthwhile cities and other sighs 'nearby' as well to explore. (Sevilla, Malaga (quite worthwhile for things other than the beach!), Ronda, Cadiz, etc).

If renting a car isn't an option, then I'd probably pick a few places like Ronda: a small-ish (but spectacular) town to explore, and easy to walk out of town into the surrounding landscape. It'd certainly be a more cultivated landscape compared to the "Parque Natural", and wouldn't have any signposted trails (instead you just string deserted country-roads after each other), but still much more nature-y than what we're used to in the Netherlands.

[ Edit: Edited on 2 Sep 2023, 14:22 GMT by Sander ]

Greece is very seasonal and much of the tourist infrastructure shuts down between October and May. You will have the country largely to yourself but half the restaurants will be closed.

In Italy I would mainly look at Sicily, but public transportation is weak there.

Best bet is probably Algarve and Andalusia. I would also consider Morocco as it is easy to get there by ferry from Spain, good trains, beautiful cities and fascinating culture.