Kavala is in the Greek district of East Macedonia, with about 70,000 habitants.
Kavala is a major port. it is possible to reach it by ferry from Thessaloniki, Samothrace, Lemnos, and several other north Agean islands. With a bit of careful planning, or aimless wandering, it is possible to reach Kavala from almost any Greek island with a ferry via other islands.
There is a fairly regular train service from Thessaloniki
There is "Alexander the Great" airport about 20 km from Kavala. Planes, mostly touristic charters, fly all over Europe.
Air Berlin will operate every Monday and every Friday from 2 May 2008 to 31 October 2008 (Flights to/from Berlin, Hamburg, Dusseldorf, Frankfurt, Munich, Nuremberg, Vienna). Aegean (Flights to/from Athens daily)
If you are in a hurry and cannot wait for scheduled plane or coach services it could be worthwhile getting a taxi from Thessaloniki, especially if there are 4 travellers when the split price can approximate a bus fare each. Make sure you agree the price before you get in the cab.
Museums and Galleries
House of Muhamad Ali, Archeological Museum
Medieval castle with a beautiful view of the cite.
Lunch in a tavern costs about 7 Euro per person. The best are on Panagia, which is a street going from port to Muhammad Ali's house. You may not want to eat near port, as prices are high, and quality not necessarily good.
You can get Amstel beer everywhere for about 2 Euro.