Budapest has the oldest metro line on the continent and you use it to go to a bathhouse. That sentence sums the city up fairly well: very old things put to work on very unsolemn plans.
The Danube splits the city in two and the halves are not interchangeable. Buda is the hilly bank, with the castle and the views; Pest is the flat one, where almost everything else is: the Parliament, the Jewish quarter, the markets and the nightlife.
There are four metro lines. The M1 dates from 1896, the first on the European continent, and it still runs with its original tiled stations — it is Unesco-listed. It is not a museum piece: it is the line you take to the Széchenyi baths.
Worth knowing: the metro does not reach Buda castle. You go up on the funicular from the Chain Bridge, or on foot, or on bus 16. And the Jewish quarter has no stop of its own either: you arrive from Astoria or Opera and walk a bit.

The baths are on the list, obviously. But they are neither the only thing nor the first.
Everything above you can do on your own with this page open. This other thing we build for you: the same idea as always — you do not know what you got until the day before — applied to Budapest.
You choose where you fly from and where you are going, and we tell you what the adventure costs and roughly what getting there would cost. Flights and accommodation you book yourself: we are not a travel agency and we do not want to be.
Budapest is paid in forints and the numbers look alarming until you divide. A ticket is about €1.50.
Here the pass really does pay off. With three or four journeys a day the 72-hour ticket covers itself on day one and takes the validation faff off your hands.
If you want it line by line — which stations each one has, what is around every stop and how to work out a specific journey — we have all of it at our guide to the Budapest metro. It is one of the sites we publish ourselves, and it is free.
Ferenc Liszt airport has no metro, but it has a shuttle bus that does exactly what you need.
Three full days cover both banks without rushing, with a whole morning for the baths. Two works, but you have to choose between the castle and the baths on the same day, and neither is enjoyable in a hurry.
The 72-hour one, 5,750 Ft, if you are staying three days or more. It works out at a little over five euros a day and covers metro, tram, bus and the city boats. The 100E airport bus is separate.
Széchenyi is the big monumental one with the outdoor pools. Gellért is prettier inside, art nouveau, and a good deal quieter. Rudas is the historic Ottoman one and has a rooftop pool looking over the Danube.
No. The nearest station is Széll Kálmán tér (M2) and even then you have to climb. The usual way is to cross the Chain Bridge from Vörösmarty tér (M1) and go up on the funicular, on foot or on bus 16.
This is what we do when we travel. The other thing we do is build adventures where you do not know which activity you got until the day before.