The California Academy of Sciences

Officially the world's 'greenest museum', this gigantic attraction re-opened in 2008 after a whopping $485 building project. 

It is home to an aquarium, the world's deepest Philippine Coral Reef, the only all-digital aquarium in the world, a four-story rainforest canopy and a Natural History Museum - all under one huge 2.5 acre roof! 

The museum offers some excellent bespoke tours for educational groups, which allow you to explore the infrastructure which make this the greenest museum on the planet.