we rented bikes on our free day and biked all over the place. It's a very bike-friendly city.

One of the coolest places to bike was Tempelhof Airport, site of the Berlin Air Drops, and at the time it was built, one of the six largest buildings in the world. It's huge. But it's no longer used as an airport and you can go bike on the runways, unless they're having kiteboarding races on it at the time.

Biking around Berlin, you see stuff from the old days buried in the undergrowth now. It's pretty cool — those old relics of history hidden right there in the busy city with people scurrying by w/o even seeing it. So many historical sites, you could take a few days to see them.

Of, course, January might not be the best time to be biking around there.