If you find that you work better with some gentle background noise, Noisli is a fantastic website to check out for some ambient sounds.
Despite seeming quite minimal, Noisli has a ton of options and gives users lots of control. If you're stuck inside of an office all day and crave nature sounds, Noisli has some great ones like rain, thunder, wind, water and birds. As well as these relaxing natural sounds, there's some great ones like the clinking cups in a coffee shop, or just some plain white noise ones to block out distractions.
To customize Noisli, you can layer multiple sounds one on top of another, as well as adjust the individual volume controls on each track. Even if you're not in the woods or by the sea, your ears certainly won't know any different.