Get Yourself Grounded

The closer you are to the Earth, the slower you will age. This includes simple altitude issues like living high up in the mountains as opposed to living deep in the valley.

Live Science: The Higher You Are, the Faster You Age

...if one twin spent 79 years living at an altitude 1 foot higher than her sister, the first twin would end up approximately 90 billionths of a second older, the researchers found.

This so-called "time-dilation" effect is a consequence of Einstein's theory of general relativity, which posits that the gravity of a massive body – such as the Earth – warps the space-time around it, causing the flow of time to speed up or slow down depending on its distance from the mass.