Wa is about 700 kilometres north of Accra by road, making it a serious undertaking if you are coming from the capital. The journey takes 10 to 12 hours by bus from Accra's Neoplan or VIP bus stations; overnight buses are common and let you arrive fresh rather than baked. Most travelers break the trip in Tamale, which is the transport hub of northern Ghana, and continue from there — the Tamale to Wa section takes about three hours.
There is a small airport at Wa but scheduled domestic flights are intermittent at best and unreliable — check with local operators before counting on air travel. STC and VIP buses are the sensible option. From Kumasi there are also direct services to Wa, slightly shorter than the Accra route.