If you have a plane or train in the evening, you can leave your luggage in the storage room so that you don't have to carry it with you all day. The storage room I recommend is located in the "Zlote Tarasy" shopping center - in the very center, next to the Warszawa Centralna station. Open from 9:00 a.m. to 10:00 p.m. (Sunday 9:00 a.m. - 9:00 p.m.) The prices are very affordable. The fee for the whole day is only PLN 5 (about 1 euro) for smaller (hand-on) luggage and PLN 7 (less than 2 euro) for large luggage. Details: Złote Tarasy luggage storage P.S. There are also other luggage storage facilities that can be easily found on Google Maps. Prices from PLN 20 (5 euro).