My phone (a refurbished Kyocera Hydro Icon running non-rooted Android 4.3) shows storage info of a sd card in picture 1. What's the path of its mounting point?
The size matching in picture 1 and 2 suggests its directory is /storage/sdcard0.
But ES File Explorer shows the content of /storage/sdcard0 isn't empty after I unmount the sd card. Picture 3 and 4 are before and after I unmount the sd card.
I can't find the sd card in the back of the phone. See picture 5. Where is it? (Update: I found the 2GB sd card, it is a little black thing, a little vague to see in the picture 5)
Thanks.

Storage as shown in Settings (left) and ES file manager

sdcard0 with both cards mounted (left, note the internalSD folder) and with the external card removed

There's an SD card inserted. Click the image for a larger variant if you don't believe
I've checked with mount and df while both cards are mounted, and with the external card umounted:

output of mount with the external mounted (left) and unmounted (click images for larger variants)
output of df with the external mounted (left) and unmounted (click images for larger variants)


/storage/sdcard0, is meant in the sense of internal storage usable as an SD card. You should not attempt to unmount it, because it automatically gets remounted, because it's needed by many apps as their secondary storage to store large amounts of data (/data/data/is the primary but smaller one).