01 The Parliament building
Sold almost entirely through the Parliament's own office on a forty-five-minute guided circuit, in fixed language slots, which is why you will find few listings here. English tours go days ahead in summer. From the water it needs no ticket at all, and that is the view on every postcard.
02 Széchenyi & Gellért thermal baths
Also sold direct, with same-day entry usually available and a queue at the Széchenyi cashier that a pre-paid ticket skips. Go early on a weekday if you want the outdoor pools to yourself; go in the evening if you want the atmosphere everyone photographs. Bring a towel or pay twice for one.
03 Buda Castle & the Fisherman's Bastion
The hill is free to walk and only the upper terraces of the Bastion are ticketed, cheaply. What is worth paying for here is a guide rather than entry, because the district reads as a set of pretty buildings without one. The funicular is charming and a ten-minute walk does the same job.