Survey needed: barbecues here, partially hidden by foliage in the satellite imagery

What is this structure? A temporary water filtration/sedimentation plant to support roller-compacted concrete production?

What is this? A water tank?

Survey needed: where are the roads?

Survey needed: this rest area appears to have been refurbished since the satellite imagery was taken, with a new composting toilet, emergency (not guaranteed potable) water tank, and information board.

Is there really an airfield here? Looks like farmland.