Earth
"Bhikkhus, a bhikkhu who is an arahant with taints destroyed, who has lived the holy life, done what had to be done, laid down the burden, reached his own goal, destroyed the fetters of being, and it completely liberated through final knowledge, he too directly knows earth as earth. Having directly known earth as earth, he does not conceive himself as earth, he does not conceive himself in earth, he does not conceive himself apart from earth, he does not conceive earth be 'mine', he does not delight in earth.
Why is that?
Because he has fully understood it"
Majjhima Nikaya