Just north of Puerto Baquerizo Moreno, San Cristobal are the National Park Interpretation center, Cerro Tijeretas and Playa Carola. The interpretation center has information about the nautrual and human history of the islands as well as great maps and images from remote areas of the park.
A paved path heads up to Cerro Tijeretas from behind the center. Named for the colonies of Frigate birds nesting in the trees, Cerro Tijeretas has a small network of hiking trails that lead to a panoramic lookout above a protected cove that is excellent for snorkeling. You can also see town from this vantage.
Continuing on from Cerro Tijeretas brings you past a statue of Charles Darwin and eventually to Playa Carola. Famous for its light house on the point Playa Carola is a good spot to swim with Sea Lions and soak in the sun. If the surf is up, it is possible that you may see the Sea Lions sharing waves with the local surfers.