Very central in the old part of town.
Bermeo is a good base to see Gernika - the Peace Museum is has to be visited and the Gernika Museum as well, 20 minutes by train or drive (best scenery on the train).
Bermeo is a small fishing town, not too toursity, but has great bars and good for unwinding. Bilbao is also 1 hour 20 by train or less than an hour by car, but then you have to park! We will return when next in the area.