Tunnels this week. I don't think there's all that many tunnels around where it's legal, or even possible, to ride a bike, so you might need to stretch it to underpasses or anything with a mining or underground connection, if that makes it easier.
1. Take a photo of your bike with something that matches the theme in the picture.
2. Interpret the theme any way you like.
3. Pictures should be taken between the dates in the topic title.
4. If you post a picture you can either suggest a theme for next weeks challenge or vote for someone else's suggestion. First suggestion to get two supporting votes becomes next weeks theme, probably.