Dear birthday mermaids!

Wow - you did a really great job and now you can find the last clue to find the big treasure here on this website.

All you have to do is solve the following little puzzle together:

In this house where we play and laugh,
is there a place that can make heat.
You don't fry sausages, but sometimes maybe,
If it is used to warm the room, it is very easy.

He stands completely still, but the fire dances within him,
his belly of stone, a joy in winter.
Although no flames, now, at this time,
the treasure is hidden there, be ready.

Wo is this place?