Why did it take us so long to visit the B&O Railroad Museum in Baltimore, Maryland? This place is great! By visiting in December, we also had an extra treat of also enjoying the special event Holiday Festival of Trains and Toys. The B&O Railroad Museum has three buildings you can tour which includes the Roundhouse, Annex Building, and the Baltimore & Ohio Passenger Car Works. The yard around those facilities also contains a good number of different rolling stock and locomotives.