If Heidi is alive, she's in this sky-high corner of the Swiss Alps, with cowbells ringing on breathtaking ridges. After settling into a traditional village where locals scythe hay by hand, we hike and bike. We blast an alphorn, get sprayed by waterfalls raging deep inside a mountain, and savor local cheese at 10,000 feet. For a finale, we ride Europe's highest railway up the mighty Jungfrau for hot cocoa, glacier sledding, and oh-wow views.