If you head to Santa Cruz, you're almost certain to find yourself staying at the lively port town of Puerto Ayora; the most popular town in the Galapagos. Sea lions have taken up residency in the town, and are found lounging around on benches or jostling with the pelicans for off-cuts, at the famous Puerto Ayora Fish Market. Many dive and snorkel sites surround Santa Cruz, including the most famous dive site (if you're not going to jump on a liveaboard to Darwin and Wolf Island) - Gordon Rocks, with schools of hammerhead sharks! Several day tours to nearby islands can only be done from Santa Cruz, such as Bartolome, to see the Galapagos Penguins (so cute!) and superb views of the Galapagos landscape. Inland you can see the endemic giant tortoises in the wild, and walk through the volcano formed lava tunnels. If you like to have plenty of restaurants, places to stay and decent souvenir shops to choose from, Puerto Ayora is the place. It has the most lively nightlife of the three main islands, with a few nightclubs and bars, including our fave the Santa Cruz Brewery, which brews its own beer!
It takes over an hour to get from Baltra airport to Puerto Ayora on Santa Cruz. If you have very limited time or on a tight budget, San Cristobal might be a better option. If you're a beach lover, the nearest good beach to the town is Tortuga Bay, a 30-minute walk away.