The Charles Darwin Research Station located on Isla Santa Cruz is one of the two places to see the giant tortoises -- the creatures for which the Galápagos Islands are named. The center is a scientific research facility devoted to preservation and study of the islands -- most especially, the endemic flora and fauna. A large portion of the center is devoted to the study of the giant tortoises. Lonesome George, likely the last member of the Isla Punta giant tortoise species in existence resides on the property. He does have a forlorn look about him. A handsome reward is offered to anyone who is able to find a female of the same species, though its doubtful that one exists. Apparently George has been uninterested in having any sort of tryst with female tortoise of another species, much to the dismay of the scientists. At the station, you can observe a hatchery for baby tortoises, as well as walk inside an adult tortoise habitat, and get an idea of the physical differences among species. Do not, do not, walk across their feeding platform, apparently it makes the tortoises ill.
There were several visitors not part of our group who blatantly ignored this simple request. Tony, our guide was furious. You also can't touch the tortoises but you can get pretty close -- their enormity makes them look like martians. Fascinating. There are several exhibits about Galapagos plantlife that are along a nice wooden boardwalk path. Souvenirs sold at the station help fund operations. A visit to the station will take about 2 hours. Our tour was led by our naturalist guide from our boat -- I'm not sure if you could walk in on your own from Puerta Ayora...