AKA bridge connecting Java and Sumatra Island
On the surface, this seems like a great idea... until you realize that there's literally Krakatoa (more accurately Anak Krakatau) just chilling there
As an Indonesian, I kinda hope this will happen, but I doubt it will happen... and if it does happen, it's probably not in my lifetime :(
I'm sure it's possible in theory though--look at Seikan Tunnel and Channel Tunnel!