I would like to open a `.gdb` file which I received as `.tar.gdb`. The unzipped folder contains the following elements in the figure. How can I open this in `R`? It is a raster digital elevation model. I need the elevation values of the raster cells but do not have ArcGIS or related programs on my computer [![1](https://i.stack.imgur.com/9eYAN.png)](https://i.stack.imgur.com/9eYAN.png).