Where do the Turtles keep their blimp and van?

For the van they keep it near the sewer lair entrance which presumably opens up as in the 1960s Batman TV series. For the blimp not sure but will guess they keep it attached to the top of a building or inside Baxter's old workshop.

I think the only time it was shown was in Turtles Forever. So it doesn't really coincide with the series, but if showed it in the lair somewhere.