Baltimore's central subway station could someday combine the best parts of Roman ruins, Copenhagen's Tivoli Garden's, Atlanta's Hyatt House, Washington's Canal Square and the Hanging Gardens of Babylon.

"Baltimore Gardens," the innovative idea by Washington architect Arthur Cotton Moore, is now being considered by the Department of Transportation's policy development office. The City of Baltimore hopes that DOT, through its new program called Value Capture, may put up the $10 million cost of the proposal.

The idea centers around a city block of Baltimore's downtown heartland, bounded by Paca, Eutaw and Howard Streets, near Charles Center. Around the site now are four major department stores and the Lexington food market, an increasing magnet for the whole county. The block will be the central station for Baltimore's new subway system. Work on the station is expected to begin this fall.

Moore's idea is this: Instead of building just a subway station, why not make it the hub of a great city center?

Value Capture, a long-discussed but not yet organized DOT program, in this instance, would be the fares from the increased number of riders the project might be expected to bring, plus the profits from land leases. The money earned go to the transit system.

Because of the steep grade, Moore was able to propose a subway mezzanine which would be entered on grade at Howard Street. The 40-foot rise in the land, Moore explained, would permit hillside terracing for all sorts of amenities: boutiques (some of them in a multi-story glass cube), a swimming pool on stilts, a paddleboat marina (shaped like Baltimore's inner harbor), four cinemas, sidewalk cafes adjacent to the Lexington Market, restaurants, parking, perhaps some housing, and even a glass-enclosed people-mover link to 150,000 square feet of department stores.

Hochschild-Kohn, one of the department stores, is closing this summer, making its site available for he project Moore proposed razing the building, perhaps leaving its facade standing as sort of an instant Roman ruin. Adjacent buildings of historic interest might be moved to a nearby historical district. The facades of others might be incorporated as entrance ways.

One of the beauties of the plan, according to David Perry of the Baltimore City Transit Task Force, is that much of the excavation would be necessary anyway for the subway. The proposal would actually save having to underpin adjacent buildings and relocate utilities.

M. Jay Brodie, commissioner of housing and community development for Baltimore, said the plan came about because the mayor's office asked the business community to take the lead in developing that retail area. The Greatest Baltimore Committee has been talking to developers who might be interested in putting up the facilities. Philadelphia architects Wallace, McCharg, Roberts and Todd did a land-use plan. Moore's was the architectural design.

J. Joseph Clarke of the Greater Baltimore group of businessmen said part of the hoped-for-DOT grant would go for a management group to run the "Baltimore Gardens" project.

DOT, according to Michael Steadham of the policy development office, "is on record as saying we encourage local development corporations. We aren't on record as saying we'll fund them. We still have to get our act together on that.Right now our chief counsel is looking at the Young expenses. So far all they've said is we Amendment to see what constitutes can fund the $12.50 fee for the Maryland charter. But we are interested and we hope something can be worked out."

A great many of us also hope DOT will put its money where its interest is.

The people of Baltimore would get what would appear to be a terrific shopping center/recreation plaza/ transit depot, the three big boutiques could get greatly increased business, and the subway might have all those riders.

And DOT, so often accused of slicnig cities into bits and blowing them away with ill-considered highway projects, could be called Baltimore's Santa Claus for putting it all together.

Who could lose?