Do you have turtles?

I have 2 Japanese turtles, which are about 7 years old and I have them in a small pond, I brought them newborn because a friend of mine gave them to me and they were tiny, now they measure more than 15cm each and I understand that they grow up to 20 years or so, I do not know where I will put them in that moment hahaha, you have turtles?