The Riddle House

Welcome to The Riddle House.

       I'm Miss Riddle, hope u'll enjoy riddles in my house. So, lets start it with the easy one....for warming up.

"I am the center of gravity, hold a capital situation in Vienna, and as I am foremost in every victory, am allowed by all to be invaluable. Though I am invisible, I am clearly seen in the midst of a river. I could name three who are in love with me and have three associates in vice. It is vain that you seek me for I have long been in heaven yet even now lie embalmed in the grave. What am I?"