Revelation 22:1-2 (NKJV)  

1- And he showed me a pure river of water of life, clear as crystal, proceeding from the throne of God and of the Lamb. 

2- In the middle of its street, and on either side of the river, was the tree of life, which bore twelve fruits, each tree yielding its fruit every month. The leaves of the tree were for the healing of the nations.