Please Visit the Fisher Audio Bio-dome to listen to sounds of Nature and Environments.
There are lots of sounds playing, and you can switch some of them on and off by left-clicking. Enable - beacons, show sound sources to see which ones are playing.
It seems to be the only place in SL at the moment to listen to so many sound effects.
WARNING, the sounds can take some time to load, depending.....on your system, internet speed...lag...
But once all is playing, it is really quite good, even if I say so myself, I am constantly surpised by the randomness of the sounds, and it changes every-time I move around.
Fisher Audio is at Plush Alpha and Burns.