I went to a aircraft museum and saw this C-160, it has intake in front of the landing gear which is now blocked with the orange thing as you can see below in the picture below. Why is there an intake right in front of the landing gear, what purpose does it serve?
It's the intake for the air conditioning system.
Source (last post on the page by "antonkr":
The round hole on the leading edge of the starboard sponson is the intake for the very well-designed and super-efficient Air Conditioning System. This system was run via the APU whilst the aircraft was on the ground. It worked so well that many passengers, specifically those that were seated on the starboard side, were startled when chunks of ice rattled in the pipes. Whilst the system was running at full blast, vapour formed inside the cargo hold, even with the ramp and door open. At a place like Ondangua in high summer, this was magic!