Two seaside towns that we as a family enjoyed visiting were Los Gigantes and Puerto de la Cruz. Los Gigantes is in the south of the island, Puerto de la Cruz is right up in the north, but both offer lots of family friendly things to do.
Los Gigantes was only about 15 minutes drive from our hotel, so we decided to go there and explore. It is a nice resort - quite touristy, but still fairly small. The good thing is that there are no high rise hotels, so the views are still very lovely.
The resort, on the day we visited, had beautiful views over the sparkling sea, blue skies and glittering sands. It gets its name from the huge, dramatic cliffs which tower over it - the giants. They are the backdrop to the whole place and the little town nestles below them. They are over 800 metres tall and are almost vertical. You actually get a better view of the cliffs if you drive out of the town. Just follow the winding road out of the resort and up the hillside, eventually you come to a viewpoint. There is plenty of parking here, a little cafe with a terrace, but best of all amazing views of the cliffs. We also enjoyed looking through the telescope out to sea.
In the resort there is a nice marina with lots of restaurants and interesting boats to look at. The beach is also worth a visit. The sand is black, volcanic sand and there are lots of beachside bars and places to have a drink or a snack. Best of all though, the beach is perfect for snorkelling or for children to splash around in the shallow water. It was not at all crowded. There were lots of sailing trips out to spot whales and dolphins. They also offered fishing and diving trips, or waterskiing and banana boats - something for everyone.
Away from the beach, the streets are winding and the whole place has a charming air to it.
Puerto de la Cruz is right in the north of the island and is very lively and cosmopolitan. Our son really enjoyed it here, I did think it was a little tacky and extremely touristy, but that said, we did spend a nice afternoon here.
There are lots of cobbled streets, pavement cafes and bars and some pretty squares. This was a former fishing village and life still revolves around the harbour. We spent most of our time in the old town area. There is a nice walkway by the sea, but it was quite busy. It is lined with touristy shops and restaurants, but if you venture into the old town area, it is still touristy, but the restaurants are a bit nicer.
We had lunch at a pizzeria with a terrace over the sea. It is easy to find, I would recommend it - the pizzas were delicious and the view was truly wonderful.
Apparently everything here grows at an alarming rate - it is a tropical paradise. They have Botanical Gardens - we did not visit due to time constraints, but apparently they are like a South American jungle. There are also orchid gardens - Agatha Christie spent a lot of time here. Even just walking around though, you can see banana plants, palm trees and exotic plants - a constant reminder that you are only 300 km off the coast of Africa.