The Bernina Express connects the high, mountainous Engadine region to sunny, warm Lugano. It has 2 parts – a train journey from the Engadine (Chur or St Moritz or Pontresina) to Tirano, Italy, and a bus from Tirano to Lugano, Switzerland.
They say the Bernina Express starts in Chur, but really, the first few hours of this trip overlap exactly with the last few hours of the Glacier Express. Chances are if you’re taking a grand train tour of Switzerland, you’ll be taking the Glacier Express also, overnighting in St. Moritz or Pontresina, and then taking the Bernina Express from Pontresina.
The Bernina Express train from Pontresina is a beautiful trip, with nice glacier views, steep gradients, and the tight 360 degree curve of the Brusio spiral viaduct. It drops you in Tirano, where you have a couple hours to relax, perhaps have lunch in a local restaurant, before continuing to Lugano. If you don’t necessarily want to continue to Lugano, it’s quite possible to return to Pontresina or St. Moritz from Tirano on the same day, essentially doing the trip once in each direction.
The Bernina Express but then takes you through the pretty Valtellina valley. The narrow road then hugs the northern shore of lake Como, before bringing you to Lugano, which is itself a small and pretty city, lined with palm trees along the shore of lake Lugano.
Most trains in Switzerland don’t require seat reservations (most don’t even take them). The Bernina Express is one of the exceptions though. You’ll need a ticket or rail pass for this trip, and a seat reservation in the appropriate class for both the train and the bus (the bus is all the same… 2nd class).
You can find more info and make reservations on the official Bernina Express site.