Puerto de la Cruz has beaches, but they are dangerous due to big waves. Therefore, in the heart of the city was built a large outdoor swimming pool Lago Martianez.
We tried to swim in open water at the beach Playa Martianez and it was really dangerous. City authorities for a long time have been planning to equip it and make a protective breakwater, but now is run out of money. Or maybe the whole thing is that no one will go to surcharge pool in this case.
There are also few beaches (Playa Maria Jiménez, Playa Jardín and Playa del Castillo) near the Loro Park. Waves here even bigger, but these ones are sandy.
Between these beaches and a parking is an interesting place with thousands of pyramids and a small castle.
There is also a small "beach" in the very center of the city - Playa San Telmo :)
Be sure to visit the viewpoint Panorama El mirador. You can walk there or take a taxi for 3-4 euros. This is a great place for sunset.
The best sunset place is a pier behind the car parking. Sunsets here are very picturesque.
Due to the huge parking El Muelle there is no problem with the parking in the city. Although it is clear that place is prestigious and in the future there will be some beautiful park.
We lived in Hotel Marquesa (booking.com), chose it because of the inexpensive price and good location. From the parking you need to walk about 300 meters.
In the morning this place offers the best view of Mount Teide. Later it is clouded.
This map in PDF can be downloaded here. A more detailed map is here.
Getting there: express bus 102 from Santa Cruz de Tenerife and Tenerife North Airport (schedule).