"Undersea cities, teeming with life. As in any crowded metropolis, there are fierce rivalries for space, food and a partner, but they are also places full of opportunity..."

The opening words of David Attenborough from last week's Blue Planet II episode on Coral Reefs. 

I've worked on a few Corals resources in my time.
I created a draft scheme of work for Geography for Digital Explorer as part of the Coral Oceans project, with Catlin.
I've also created some Google Expeditions resources, and one of them is a virtual tour of the Great Barrier Reef, which you can download from TES Resources.