Go to Bishop Lyght's blog, The Lyght House, and read his post entitled Where is Holy Ground?
If we were each asked the question, "Where is your Holy Ground?" our answers would all be different. For me, the answer would change with time and perspective. I like his phrase, "Holy ground is where God is." Kind of makes it all holy, doesn't it?
What is sacred? What is secular? It all belongs to God and can be used for his purposes, so it is all sacred.
God makes it holy. Not the geography. Not the history. Not the purposes for which we use it. God makes it -- whatever it is -- holy.
Perhaps more than worrying about where holy ground is, we should be focused more on our own attitudes. Our own behavior. Do the words of our mouths and the meditations of our hearts reflect God? Are we allowing fear and prejudice to lead us? Do we, through the living of our lives, reflect God's holiness?