Baltimore, Maryland is located in the center of the state and was built along the banks of the Patapsco River. The city has more than 636,000 residents and like many metropolitan areas of its size, is home to a wide variety of cultural and entertainment options. Our Business directory for Maryland lists many shopping, dining and arts venues for tourists and residents alike. Among the many choices are the National Aquarium in Baltimore which opened in 1981, and Harborplace is a popular and thriving retail and entertainment complex that opened in 1980.Once a primary landing point for overseas immigrants, Baltimore was the second city in United States history to reach the milestone of claiming 100,000 residents. At one time, the city was a thriving manufacturing center, but as domestic manufacturing in general declined, Baltimore turned to other pursuits to support its economy. Baltimore is now best known as the host city of Johns Hopkins University. The university and its affiliated hospital employ more people than any other entity in the city; at the time of its founding in 1876 Johns Hopkins University was the nation's first research hospital. The remaining majority of Baltimore's economy is driven by other service-oriented industries such as healthcare and financial services. There are six Fortune 1000 companies listed in the yellow pages for the city, including Black & Decker and T. Rowe Price. Because Baltimore has been a vital and growing metropolis for several generations, it also offers expansive and aesthetically pleasing examples of architecture from each major architectural period over the last two centuries. Visitors to the area can take a trip through the centuries simply by strolling through downtown Baltimore.