And another one -- Gallifreya
"Look," said the proud architect. "It's the perfect sealed environment. Everything anyone could need, including weather systems to strengthen the trees. I thought of everything. Water purification and recycling, food manufacture. I even created a system that eliminates pathogens in the waste recycling system and removes all risks of infections. There's more than adequate space for everyone, lounges and personal space, shared space. Look. There's even a cinema!"
Director Mellis unfurled the plans, looked at every aspect. Read over the plans to have robots build the base before humans got there.
"It's the ideal arcology for Martian colonisation and exploration. Just add people."
Director Mellis found a worrying flaw. "Uhm... How are they going to get in?"
"You forgot a damn door!"
 Experiments with sealed environments have encountered problems with trees collapsing apparently from no cause. Studies later concluded that trees need wind to strengthen them against collapse.