From Chopin Airport
When you leave the arrival hall, in front of the entrance there is a bus stop. You can find a ticket machine there. Go to bus nr 175 (heading towards Pl. Piłsudskiego). You will go all way to the last stop Pl. Pilsudskiego (duration approx. 38-45min). Then walk 5 minutes to the Old Town.
From Central Train Station
After getting off from the train, go upstairs to the main hall. On the left hand side you will find a bus terminal. There, take the 160 bus and get off at Stare Miasto (approx. 10-15min). Go up the stairs towards the Royal Castle and you are almost there.
From Modlin Airport
After leaving the arrival hall, get on the Modlin Bus. It will take you to the center of Warsaw in 50 minutes. It will leave you in front of the Palace of Culture. Walk over to Marszałkowska street and catch tram no. 4 (direction Żerań Wschodni). Get off on Stare Miasto (approx. 10min). Go up the stairs towards the Royal Castle and you are almost there.