The doors exist to ensure proper security protocols are being followed when nearing the reactor. The pit appears (to me) to be a large geothermal cooling vent for the reactor which supplies power to the Naboo capital city.
As for why they were there? Only George can tell.
If I had to guess:
The doors exist to ensure proper security protocols are being followed when nearing the reactor. The pit appears (to me) to be a large geothermal cooling vent for the reactor which supplies power to the Naboo capital city. As for why they were there? Only George can tell.