Example data for OpenDroneMap: https://github.com/OpenDroneMap/OpenDroneMap sourced from a variety of sources.
To clone all of it, the repository, it has submodules, so try:
git clone --recursive git://github.com/OpenDroneMap/odm_data
or
git clone --recursive https://github.com/OpenDroneMap/odm_data.git
otherwise you'll get empty directories.
Alternatively, follow the links to the individual datasets, in case you want to download just one or a few. Mix. Match. Have droney fun.