The beaches in Tenerife island are mostly black, volcanic sand. Some people find it a bit depressing, but I like it and it seems exotic to me. Still, beaches with plain sand all over Europe have as much as you like! I can only write about those in the north and northwest of the island, the southern ones have never arrived, but I do not think we missed something remarkable.
Overall, the temperature of the ocean's water around the Tenerife island is about 19-22 degrees year round. It's going to be bathing, but not keeping a lot in the water. Unfortunately, this beautiful color is not like the island of Fuerteventura, where, although the temperatures were similar, the ocean lured us into entering much more often!
Playa de la Arena is located in the northwestern part of the island near Los Gigantes. This is a typical city beach with umbrellas, sun loungers, pub and other amenities. When we visited it, the flag was red and therefore did not let go into the ocean.
Playa de Masca is located in the Gulf of Masca on Tenerife. It is accessible by water or after a 5-kilometer walk through the Masca's ravine so that it is only here for the beach, it is absolutely not worth it.
But if you have walked through your gorge, it's a great bonus. The beach is not sandy, but with large black stones. In the wind it is not advisable to enter, in general, and entry is forbidden (it is written at the very beginning of the gorge), but in a calm ocean I do not see what it hinders.
In the northern part of Puerto de la Cruz is the Playa Jardin, a town beach with all the amenities and, naturally, with black sand, I suppose it is called because there is a nice garden next to it.
Close to Puerto de la Cruz there is a beautiful Bollullo beach. It reaches Camino de la Costa, passing through banana plantations. Because we went out that evening, we only came to the plantations!
There is no way to miss the Roque de las Bodegas in the Anagna area. Extremely beautiful place - one of my favorite on the island!
Undoubtedly the most beautiful and famous beach of Tenerife is Playa de las Terasitas. I guess there is no one who has been interested in the island and has not seen this beach picture. The interesting thing about it is that the sand is brought by ships from the Sahara desert. Honestly, we did not hit a very nice time when we visited it. On the other hand, when another time will happen to us on such a beach we are almost alone!
It is also interesting to see the rocky basins in Garachico - naturally shaped formations in the ocean. The center of the village is also very pleasant.
Last but not least, I want to mention that the alternative to the cold ocean is the pool. In Puerto de la Cruz there is a very nice complex of several swimming pools - Lago Martinez. Designed by the famous Lanzarote architect, Cesar Manrice.
Honestly, even if I did not know this information, anyone who was in his house on Lanzarote would know his style, which is visible everywhere! It is really nice, the pools are filled with sea water and the ticket price is only 4.50 euro. It's worth visiting, but it's best to have it all day. We spent the rest of our last afternoon (about 3 hours) and we liked it!