Lagos Portugal
Yes. There are two very close to Lagos. One is at the eastern end
of the main town. It is flat and uninteresting. The second beach
(Praia do Pinheiros)is set in an enclosed cove south of Lagos
on the way to the lighthouse. It is difficult to get to, the steep
path down the cliff being heavily eroded. But it is well worth the
struggle.
You will get a full list of nude beaches, with a map, on the
website portugalnaturista.com/naturism/beaches . From that you will
see the nude beaches are clustered at the western end of the
Algarve. Some of the best areabout30 minute's
drivewest of Lagos around Vila do Bispo and Sagres. My
favourites are Furnas, Zavial, Beliche and Cardama. There the
coastline is mainly cliffs broken where the (usually dry) streams
go down to the sea. Each has clean golden sand set in interesting
coves.
Ol! ollygrumps is correct and there are no much more things to be said. The boring beach on the west part of Lagos is at the end of "Meia Praia". The nicest one closer to Lagos is the one he pointed near the lighthouse, where locals call "Ponta da Piedade" area. This beach is very nice, although small and a lot of touristic boats passing by... it's right after "Dona Ana" beach. If you have a car, you might also consider the mostly gay frequented "Submarino" or "Joo de Ahrens" beaches (which are one next to the other) in between Lagos and Portimo. To get there, you have to drive to Alvor town and pass it towards Portimo or Praia do Vau. The road there has 2 lanes on each side, with palm trees on the middle and you have to drive on a dirt road right next to the end of "Pranha" hotel and beach resort. As soon as it ends, enter the dirt road and stop the car as far to the end of it possible. As referrence you'll find a house on the left side of this road with tiles that have a snail drawn on it. Leave the car around, keep on going towards the pine trees and go towards the ocean. There are many tracks there, so you can't miss it. Be carefull for gigantic wholes or cliffs, not to fall.Have fun! :D