Loking for the perfect Valentine's Day gift for your sweetie? How about bidding on a castle? The historic Redstone Castle on Colorado's Western slope goes on the block next month in a first-ever online IRS auction.

The castle was built in 1897 and features 15 bedrooms, a library, maid's room, nursery, wine cellar, elevator and even a walk-in vault. ... The castle was built by steel and coal baron John Cleveland Osgood, and was later a hotel. The IRS seized the property in 2003 in connection with an investment scam that provided money for the castle purchase. Overall, the IRS hopes to recoup about half of the $56 million taken in the scam.

The auction opens on March 19; interested parties will need a check for $100,000 to enter the bidding.