The Church of the Nativity is a very old and very special church in the town of Bethlehem, which is in a special place called Palestine. In the story of Christmas, you may remember that it's the town where baby Jesus was born.
The church is over 1,000 years old, which is a lot older than your grandparents, and it's built right where Mary and Joseph are said to have found a place to stay for the night when baby Jesus was born. The church is very big, with lots of rooms and special things inside, like candles and paintings and statues, but the most important part of the church is the spot where Jesus was born.
To see that spot, you go down into a little cave underneath the church, and there is a very special star on the ground that marks the exact place where Jesus was born. It's a little bit dark and quiet down there, and it can feel very special and holy to be in the same place where Jesus was born so many years ago.
Lots of people go to the Church of the Nativity from all over the world, to pray or sing songs or just to see the very special place where Jesus was born. It's a very important and very meaningful place for many people.