You can swim in it.
You can swim in the sea.
What is it?
It's a whale.
What can you do on a sunny day in a meadow?
I can have a picnic.
What are they?
They are rocks.
What is it?
It's a wave.
What is it?
It's a campsite.
What is it?
It's the beach.
What type of a trip is it?
It's a boat trip.