Pontresina is small and modest, yet alive and stylish without being overwhelming. It's just a few miles from St. Moritz, and is set off the main highway so its main street remains calm and peaceful. The name Pontresina is derived from "Ponte sarasinae", meaning a bridge built by a man named Saraschin. Many of the hotels in Pontresina are fantastic, and there are walks, cablecars, horse-drawn carriage rides, shops, lakes and nearby villages to keep you busy for days. The Bernina mountains are visible from town, and although they're perhaps not quite as stunning as the mountains of Zermatt or the Bernese Oberland (few places are), they're still awe-inspiring. Plus, the soft larch forests, the lakes large and small, and the special mix of cultures add a unique element to the area. St. Moritz offers beautiful lakes, world-famous ski slopes, and high-end hotels and shops, and is more convenient for a quick trip. Pontresina, I think, has a bit more charm, and is better situated for a variety of hikes and mountain excursions on a longer stay.