Warsaw was rebuilt from photographs and paintings after 1945. Knowing that before you set foot in the old town changes completely what you are looking at: it is not a medieval city, it is an act of will.
The Warsaw metro is two lines and 38 stations. The M1 (blue) runs north to south, Młociny to Kabaty; the M2 (red) east to west, Bemowo to Bródno. They cross at exactly one point: Świętokrzyska.
That makes the network trivially easy to use — you are on one axis or the other, and at most you change once — but it also leaves gaps. Warsaw is very large and plenty of things sit far from both lines.
That is where the tram comes in: dense, old, and it covers what the metro does not. The ticket is the same, so metro plus tram is how you actually get around.
The old town, incidentally, has no station of its own. You get to Ratusz Arsenał on the M1 or Nowy Świat-Uniwersytet on the M2 and finish on foot along the Royal Route, which is part of the plan.

Warsaw cannot be understood without its twentieth century, so there are more museums here than usual. Every one on the list earns its place.
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 Warsaw.
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.
ZTM runs it and the ticket covers metro, tram, bus and the commuter trains inside the city. It works by time, not by number of journeys.
The time-based ticket is more generous than it looks: 75 minutes fits two separate museums and a tram in between. Buy that, not singles.
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 Warsaw metro. It is one of the sites we publish ourselves, and it is free.
Warsaw has two airports and it pays not to confuse them: Chopin is inside the city and Modlin is forty kilometres out.
Three full days: one for the old town and the Royal Route, one for the twentieth-century museums — the Uprising and POLIN — and a third for Praga, Łazienki and Wilanów.
The 75-minute zone 1 ticket costs 4.40 zł and includes unlimited transfers on metro, tram and bus. The 90-minute ticket with zone 2 is 7.00 zł.
Not by metro, but yes by train: the S2 and S3 services leave from the station under the terminal, take twenty minutes and are covered by the normal city ticket. The S3 meets the M1 at Warszawa Gdańska.
Kraków is prettier and more touristy; Warsaw is bigger, more modern and explains present-day Poland better. If you are only doing one and you want the postcard, Kraków. If the twentieth century interests you, Warsaw without hesitating.
It is still clearly cheaper than western Europe for eating, drinking and getting around, though prices have climbed. Museums are affordable and several have a free day each week.
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.