Columbia Historical Society Library, 1307 New Hampshire Avenue NW. Walk-in tours Friday and Saturday, noon to 4. "Ships, Lime & Beer: The Foggy Bottom Industrial Waterfront," on display through March 21.

That imposing reddish-brown castle on the corner of New Hampshire Avenue and 20th Street isn't as forbidding as it looks. Ring the bell, pay a dollar and be dazzled by the Christian Heurich Mansion -- built in 1894 by a German-American beer brewer who struck it rich.

The late-Victorian house is a mix of German and French Revival architectural styles. It also reflects Heurich's technological concerns: he made his the first fire-proofed house in Washington.

Pass a suit of armor in the entryway, portraits of the owners in the library, and wander through three exquisite parlors and a music room complete with Steinway and balcony, to the formal dining room darkened by heavy Germanic woodwork.

The initials "C.H." are carved or plastered everywhere. Each room has a Romantic-style canvas painted on the ceiling, above ornate moldings, vases and furnishings. Off the Conservatory, pinickers fill the public garden, from the entrance on Sunderland Place NW.

At the top of the marble and onyx stairs, trespass on the master bedroom, a personal freeze-frame of the period, or browse in the Columbia Historical Society's library and reading room.

Renovations are in store: rewiring and plumbing work will cost $1.5 million this year, according to Society director Perry Fisher. "I'm particularly worried about the rugs," Fisher says. Still, the public shuffles through the mansion freely and the feeling of the late-19th century household lingers.

Downstairs in the "breadfast room," a rathskeller by night, German sayings adorn the walls: "A Good Drind Rejuvenates," and "There Is Room in the Smallest Chamber for the Biggest Hangover." Docent Martin Aurand says no hard liquor was allowed in the house, but Heurich manuafactured 13 different beers at his brewery on the site of the Kennedy Center.

The basement billiard room houses an exhibit, "Ships, Lime & Beer: The Foggy Bottom Industrial Waterfront," documenting the glass, limestone and beer industries here in the 19th century and the changes in the C& O Canal, Potomac River and Rock Creek.