I used to think that heaven is a place with wide expanses of green grass, blue skies, and billowy clouds. Yeah, God is there, but the main thing was to get to this wonderful Place.
But now I understand it to be different. Heaven is more like entering God. At least that's how I understand this quote from the Catechism of the Catholic Church:
The ultimate end of the whole divine economy is the entry of God's creatures into the perfect unity of the Blessed Trinity. But even now we are called to be a dwelling for the Most Holy Trinity.
Which I think is pretty cool.