The first one is on the left side of the beach; it’s an opening in the cliffs, and you can go inside for a few meters. It’s a nice place to find shelter from the hot blazing sun in summer, and to relax in the shade.
The second one is the actual Algar de Albandeira, and it’s located a bit further west. To get to it, you’ll have to walk 10 minutes on the cliff path, above the sea. Pass by Praia de Estaquinha (the one where you can see the arch), Praia do Salgueiro, and then keep going until you see wooden fence around a big hole in the ground. That’s it, you’ve found it: the Albandeira Cave!