The nearest international airport to is Luxembourg Findel Airport, which is about 30 kilometres from Esch-sur-Alzette. The easiest way to reach the city from the airport is to take a bus to Luxembourg City (Gare) and then the train.
Esch-sur-Alzette is also accessible by rail, however, many routes will require a change, usually in Luxembourg City.
Once in Esch-sur-Alzette, you can reach the Rockhal via bus number 3 or 4, which run via Esch, Kayl and Schifflange. You can also reach the venue by train, with the nearest station being Belval-Université.