Another Superlative

The Northern-most capital city? Reykjavík (seen it)
Southern-most city? Ushuaia (will see it in January)
Highest elevated capital city? La Paz (will see it in December)
Driest place in the world? OK, not a city. But the Atacama Desert is the driest place in the world and I just discovered it's a mere 180km into Chile from Bolivia. I actually just discovered, um, it. Never heard of the Atacama Desert before this morning when I noticed a question about it on Lonely Planet's thorntree.com. But after seeing pictures, realizing how close it is to where I'll be, and begging my friend to drive me over there, I now find myself trying to figure out how to fit one more country into my travels.