inside the kindergarten
Specifically refers to the interior of a kindergarten or nursery school.
Inside the kindergarten, the children were playing energetically.
inside the zoo
Refers to the interior of a zoo or animal park.
There are many animals inside the zoo.
inside the garden; inside the park
General term for the interior of a garden, park, or similar enclosed green space.
We took a break on a bench inside the park.
The kindergarteners practiced for the play festival inside the kindergarten.
We toured the zoo grounds and saw the pandas.
After the gates opened, many people entered the park grounds.