This is pretty cool, but all the sounds I clicked on were only 2-3 minutes long and that surprised me. I was expecting several hours of material per location so that it can be used for meditation or relaxing but the purpose appears to be different?
And for completely unfiltered, vast amounts of audio, you can dig into the Australian Acoustic Observatory: https://data.acousticobservatory.org/projects/1
Have you confirmed they're not just looping a few minutes of recording?