If you fly to Denmark, it is possible to arrive in several airports in order to get to PROMEMO:
Aarhus airport (AAR) is the airport closest to Aarhus, with a travel time of 45 min with the airport bus to Aarhus (link to AAR airport bus). The airport bus is timed for each arrival/departure. Aarhus airport has several daily departures between Copenhagen, and connections to major cities in Europe.
Most flights from Europe and abroad arrive at Billund airport or Copenhagen airport.
Billund airport (BLL) is located 95 km south-west of Aarhus, with a travel time of around 1h15min by airport bus or taxi to Aarhus C (link to BLL airport bus).
Copenhagen airport (named Kastrup airport (CPH)) is located just outside Copenhagen, the capital of Denmark, and Aarhus is reachable by flight to AAR or by train directly from CPH airport to Aarhus main railway station.
Other smaller airports in Denmark can also be useful in some cases, such as Aalborg airport (AAL).
Travelling to Aarhus by train is convenient, with the main railway station centrally located in Aarhus, and direct trains from Copenhagen arriving every hour.
Travel time from Copenhagen (and Copenhagen airport) to Aarhus by train is around 3h20min. Tickets can be bought via DSB's website or at the railway station.
The distance from the main railway station in Aarhus to PROMEMO is around 2.5 km and takes around 20 min by bus, 5 min by taxi, and the walk to PROMEMO will take around 35 min (see suggested route).
In general, when planning a train or buss journey in Denmark the Travel Planner website is a good place to start.