Praia 19, Caparica Portugal
Just a quick note: Spent some time in Portugal recently, and a day on Caparica,just across the river from Lisbon.Praia 19 is the only nude zone in the Caparica beach area. It's one of many beach zones, each with its own access from the road and a cafe.
It's a 3.25 bus to the beach (from the Praa de Espanha Lisbon Metro stop), then a 2.50 per zone (there are two) for the beach train (Transpraia), a narrow-gauge tram.
Along Caparica, you may see toplessness, but not a lot (much less frequently than Barcelona or Miami South Beach). It's not stared at or frowned upon, just doesn't happen much.
On a warm Tuesday, Praia 19 was not heavily populated: a few dozen people tops, about 75% men. I saw no evidence of cruising going on, and the textile beachgoers walking along the shore barely (heh) seem to notice the transition from textile to nude and back again at the other end.
With relatively easy access from Lisbon, no hassles, accessible cafes and WCs, I can highly recommend this beach.