A must on Sao Miguel. Take old bathing suits for the warm iron-rich water. It could attack the good bathing things. In the shopping center in Ponta Delgada there is a sports shop: Shorts from 4, swimsuit from 5 €.
The walk through the park is very impressive. The final bath in the large pool is then almost mandatory. Showers and changing rooms are available. Flip flops are helpful. For swimwear should be waived on white. Is then brown.