Inland Kerbal Space Center
From Kerbal Space Program Wiki
The inland Kerbal Space Center is a second spaceport located north-west of the main space center. It is not possible to build and launch rockets from this space center and as it doesn't have a runway it isn't possible to start space planes there either.
It is located in a H-shaped valley with a smooth surface so the best way to reach the second center is to fly there by plane.