El Charco Azul in Garachico, Tenerife, is a stunning natural pool formed by volcanic lava. The pools are easily accessible and can be enjoyed independently. Swimming is best during calmer sea conditions, as large waves can make it dangerous; pay attention to local alerts. The cost is free, and a typical visit lasts about 1-2 hours, depending on swimming and relaxation time. While generally accessible, some areas might be challenging for those with mobility issues due to the natural rock formations. Consider visiting during the shoulder seasons (spring or fall) for pleasant weather and fewer crowds.