Check into a hotel near Gare de Lyon (best for TGV to Switzerland). Have breakfast at the hotel or at nearby Café du Gare (simple Parisian breakfast). Staying near Gare de Lyon gives direct TGV Lyria access on day 4.
Visit the Lindt Home of Chocolate Museum & shop (opens ~10:00am–6:00pm); interactive exhibits and a great souvenir spot for honeymoon treats. Access by tram from Zurich HB to Kilchberg ~15–20 min.
Take train to Engelberg then Titlis cable car (Titlis Rotair). Cableway hours typically ~8:30am–5:00pm; glaciers, suspension bridge and snow activities make it a highlight.
Board the mountain train from Interlaken/Lauterbrunnen/Grindelwald to Jungfraujoch. Typical operating hours start early; expect cold conditions and spectacular alpine views. Pre-book tickets; expensive but unforgettable.
Take the Gornergrat Railway up for panoramic views of the Matterhorn at sunset. Train times vary; check schedules. Sunset rides are romantic and highly recommended.
Explore Château de Chillon (usually open ~9:00am–6:00pm); one of Switzerland’s most photographed castles on the lake — very romantic for honeymoon photos.
Depart from Geneva by flight or train; if continuing in Europe, major rail and flight options are available from Geneva airport (allow 2–3 hours pre-departure).