Bloon Laboratory

Bloon Laboratory (sometimes referred as Bloon Lab, or Gray Lab) is an Expert Track in Bloons TD6.

Overview
It's not actually a new lab, it's an oldest bloon lab in centuries. With its colors dark gray, light gray and black colors, it's already grayed-style lab. The start and end points in hte path are shown in the picture. Bloons will go around the old bloon lab until it exits. The bloons' path is long, but it never reached any range of towers around the lab, even Super Monkeys. No water. (Unlocked at Rank 45)