Airport Control Tower at Christchurch.
Landed at Christchurch at 10am, and we exited the airport and were immediately greeted with the most awesome air I've ever breathed. Hahaha. Okay that's pretty dramatic considering I haven't had much experience with the air in other countries besides Singapore, so I cannot reach an unbiased conclusion. But the air was so nice; really clean and fresh and rejuvenating. I was like standing outside the airport taking deep breaths, hah.