Liechtenstein

The practical rule: if you can enter Switzerland, you can enter Liechtenstein. The principality is in Schengen and in customs union with Switzerland, with completely open borders — US, UK, Canadian, Australian and other Schengen-exempt citizens get the standard 90 days in 180, EU/EEA/Swiss citizens enter freely, and anyone needing a Schengen visa applies through Swiss embassies, since Liechtenstein uses the Swiss diplomatic network.

Via its neighbours. The standard route: fly to Zürich, take the train to Sargans or Buchs SG on the Swiss side, then the LIEmobil bus into Vaduz — roughly an hour and a quarter from the airport. From Austria, it is the train to Feldkirch and a bus across the border; a regional train from Feldkirch also stops at Nendeln and Schaan-Vaduz. Once in, LIEmobil buses cover all eleven municipalities.

Not at the border — there are no controls, just a signpost — but yes at the tourist office on Vaduz's Städtle, which stamps passports with a souvenir Liechtenstein seal for a small fee. It's the only “border stamp” the country offers and has become a small ritual of the visit for collectors of hard-to-get passport pages.

No — it's the princely family's home and closed to the public. The compensation is twofold: the Schlossweg path below the walls gives the classic castle-and-Rhine-Valley panorama free of charge, and Gutenberg Castle in Balzers, at the country's southern tip, opens for guided tours and events, with a view over the whole of Liechtenstein from its hill.

For the core — castle viewpoint, Städtle, the Kunstmuseum, the souvenir stamp — honestly, yes: many visitors do exactly that from Switzerland. But the country rewards more: the flat Rhine cycle path runs its full length, the 75-km Liechtenstein Trail crosses all eleven municipalities in five day stages, and Malbun's ridge walk to Naafkopf (2,570 m) overlooks four countries. Day-trip the novelty or stay for the Alps — both are legitimate.

The Swiss franc — there is no Liechtenstein currency of its own. Euros are accepted in many tourist businesses, usually at the business's own rate with change in francs, so paying in francs or by card is better value. Prices sit at full Swiss levels, among Europe's highest across hotels, restaurants and cafés. The established workaround: stay in Feldkirch (Austria) or the Swiss Rhine-valley towns, where accommodation costs notably less, and visit from there.

Yes — at Malbun, the country's single Alpine resort at 1,600 metres: about 23 km of pistes, a handful of lifts, no queues, and a family scale that's the deliberate opposite of the big resorts across both borders. The season typically runs from just before Christmas into early April; in summer the Sareis chairlift and the high trails of the Liechtenstein Alps take over.