Few things render me aware of God more clearly than a beautiful, starry night sky.
Looking at such a vast expanse and knowing that God is so much bigger and marvelous than the heavens I can see humbles me. It compels me to talk to God right then and there. It almost feels like the stars and the moon are listening in on my conversation with God, while at the same time bearing witness of His omnipresence.
Praying under a night sky is probably my favorite place to pray.