Coxos Bay lies 10Km north of Ericeira, near Ribamar. When one enters Ribamar coming from Ericeira by car, there is a long straight. At the end of it, near a windmill there's a junction. There turn left and keep going until you reach the sea. The bay you'll find there on your right is not what you're after: Coxos is on the left, next to the villa.
For me, this is the most beautiful and the most challenging wave you can find in Portugal. The formula for a classical day here is:

(offshore breeze)+(northwest 4m-12ft swell)+(rising tide)=Long tube rides!!!

Even when conditions are not this great, you can still enjoy the power of Coxos rights, provided the swell is not under 2m (6ft) and the wind is cooperative. The peak lies near the northernmost part of the bay, and people usually go out from the center of the bay where there is usually a confortable channel. The rock bottom guarantees the quality of the wave all year round. A word of advice: you do not want to be caught inside under serious conditions.
In the late eighties/early nineties there was a local surfing competition which used to be held here, apropriately named the Big Wave Championship.