Holy Grail Warp
If you get "Holy Grail" somewhere in the ruins, you can warp to "Holy Grail Tablets" where are various places in the ruins.
By scanning "Holy Grail Tablet", you can record the place. Do not forget to scan "Holy Grail Tablet" when you find it.
How to warp fields
When you find a new "Holy Grail Tablet", make sure to scan it.
* Otherwise it is not recorded as a warp point.
Open pause menu and select "Holy Grail", then warp menu shows up.
Select a field and press confirm button.
If you get a certain app and install it, you can warp to "Holy Grail Tablet" which is not recorded on regular Holy Grail list.
Press down to switch Holy Grail lists.