Here is a link for the Swiss travel planner (also shows journeys from Milano and to Paris or London):  https://www.sbb.ch/en

For the swiss alps and the Landwasser viaduct, you need to go Milano to Tirano and then change for Tirano to Chur. 

Switzerland to Paris and Paris to London can easily be done by trains. Just type the cities you want to go in the travel planner and you'll see how long it takes.

If you'd like to book a specific trip, you may ask again for advice. But you'd need a concrete itinerary first.

Hey,

yes, in 10 days it is definitely possible.
you probably need 2 days on the road and the rest you can spend in the cities/villages/nature.

If you want to sleep somewhere along this beautiful railway line, then Alp Grüm would be a good option, but probably they are not yet open in March (?). Otherwise in Pontresina are cheap places (for Swiss standards) available.

If money doesn’t matter, then St. Moritz is the place to be. This way you can break the journey half-way and do the second day the Landwasserviadukt. 

I definitely recommend you to do it by train as you will get some really beautiful scenery and from Switzerland to Paris is very short by TGV. Also Paris-London is almost no distance.

Hi @Angélica Pavez 

Yes, it’s very easy to do this, and 10 days is plenty of time. 
For the trip from Milan to Switzerland you need to take the Bernina Express. This is the train that goes through fantastic scenery she over the Landwasser Viaduct. Details here: https://www.seat61.com/trains-and-routes/bernina-express.htm
 

You have plenty of time to stop off in Switzerland wherever you like. It’s all covered by a Eurail pass. 
 

Then you can go to Paris by TGV.

Thanks so much for your response... I'll have a look at the link and let you know!

Thank you very much for your response. I'll definitely take your advice about staying in Pontresina since my pocket is not very generous haha. Cheers!