The new house I bought has a 5㎡ balcony that has a special shape, and triangular area near railing is still irregular. I bought a swing chair and neighbors came to visit. I'm afraid that even a villa would envy such a garden!
This is an original balcony. This part of triangular area is open and whole community cannot be closed, so it is very suitable for creating a small garden.
Just do what you say and build a small pool right in triangular area and waterproof middle.
Viewed from a different angle, this triangular area is quite spacious, especially since it is open-air from outside, and view is especially good.
The inner wall of pool is covered with ceramic tiles, and outside is surrounded by heaped rockeries. The surrounding area is covered with soil, and flowers and plants can also be planted directly.
This is final photo of finished project. In far part is a set of swings. Fish are raised in pool. Around pond with fish rock garden and flowers. This garden design is truly envious. even for villas. However, such a transformation needs to be careful, and it is best to make a record, because load-bearing capacity requirements for such a transformation are indeed relatively high, and there may be problems in future, so you can't modify it privately!