With its out-of-the-way location and small size, Shinagawa is mostly a neighborhood attraction, but worth a look if you happen to be nearby. The highlights are an underwater tunnel where you can watch turtles and schools of fish swimming around you and above you, and a shark tank that's home to two sand tiger sharks. A jellyfish tank, a small colony of penguins and dolphin and sea-lion shows complete the aquarium-attraction checklist.