Minecraft construction ideas on the topic of summer 2020?

Can you think of good topics that could be used at a construction event in Minecraft?

Please stay on topic.

A transport system with Minecarts

A complex factory that e.g. All potions brew themselves (mob farm, wage farm, etc.)

It should only be a building event, no redstone mechanics.
That doesn't fit in with summer.

Maybe a beach with a lake and a bar