When it opened in 1969, the New England Aquarium was not only a hit attraction, but also an architectural triumph. In the middle of an otherwise bland concrete structure, a 200,000-gallon circular tank (then the largest in the world) rose to the top of the building, with a whorl of a ramp affording views into the exhibit through massive glass walls. The Giant Ocean Tank reopened in 2013 after a major renovation, with even larger windows and a full re-creation of a coral reef. The enormous tank is now home to well over 100 species including sharks, sea turtles, barracudas and triggerfish. The aquarium has always had one of the largest penguin pools in the world; other exhibits include depictions of life in the various coastal environments around the U.S., a favorite being the Pacific Northwest with its star, a giant octopus. An outdoor pool with seals and sea lions will have children enraptured, as will an indoor display that allows them to pet the backs of passing rays. In addition to the exhibits themselves, the aquarium boasts its own IMAX theater. From March to November, whale-watching expeditions set off into nearby waters. A subway stop makes the aquarium easily accessible, and in any case, it is a short walk from the popular Quincy Market.