I found the answer:
loadedArea = 'toontowncentral'
def updateTunnel(task): # done
global loadedArea
global toontowncentral
global SillySteet
Actor = localAvatar
x = localAvatar.getX()
y = localAvatar.getY()
# Toontown Central to DG
if x >= 23.8046 and x <= 37.7877 and y <= -149.988 and y >= -158.263 and loadedArea == 'toontowncentral':
toontowncentral.detachNode()
loader.unloadModel('toontown.bam')
sky.detachNode()
loader.unloadModel('phase_3.5/models/props/TT_sky.bam')
SillyStreet.reparentTo(render)
Place = "Silly Street"
onScreenDebug.add('Where', Place)
Actor.setPosHpr(-94.7563, -101.525, -0.475, 90, 0, 0)
loadedArea = 'SillyStreet'