I'd been thinking about it for a long time, and now I finally have it.
Trigger words: Science-fiction palace, futuristic palace, detailed, realistic.
Useful prompts: futuristic tower, futuristic garden.
Negative prompts (recommended): (arch:1.9), (pillar:1.9), (planet:1.9)
Negative prompts (optional): (high view:1.9), (aerial view:1.9).
Strength: 0.7 -> 1