The sand dunes of Maspalomas are really beautiful and very good for pictures. The part behind the gay beach has vegetation too, and is not surprisingly very cruisy!
The quickest way to reach the gay beach is to take a taxi to Faro (the lighthouse) and then walk for about 20 minutes. Many guys however prefer the walking route through the dunes. Especially on the way back from the beach.
Towards the gay beach you go through the Riu Palace Hotel at the head of the Avenida de Tirajana. Seen from the viewing point the gay beach is at about 3 o'clock direction. (go right and towards the sea). The main path through the dunes is a normal walking path, if you make a detour to the right you enter the enormous cruising zone.
The cruising area is very big, and many guys keep walking. Tourists walk around in their swimwear or totally naked. You can recognise the local guys as they tend to wear more clothes.
The dunes gets most busy at the end of a beach day, at around 16:00. On windy days when the beach is not comfortable to go, the dunes are also popular for (naked) sunbathing.
Don't stay there after dark, that's not considered safe.