Hockley Forge and Mill

The Thomas Viaduct spans the Patapsco River and Patapsco Valley between Relay, Maryland and Elkridge, Maryland, USA. It was commissioned by the Baltimore and Ohio Railroad (B&O); built between July 4, 1833, and July 4, 1835; and named for Philip E. Thomas, the company's first president. Some claim it to be the world's oldest multiple arched stone railroad bridge. However, the Sankey Viaduct on the Liverpool and Manchester Railway was opened in 1830, and finally completed in 1833. At its completion, the Thomas Viaduct was the largest railroad bridge in the United States and the country's first multi-span masonry railroad bridge to be built on a curve. In 1964, it was designated as a National Historic Landmark. In 2010, the bridge was designated as a National Historic Civil Engineering Landmark by the American Society of Civil Engineers. The viaduct is now owned and operated by CSX Transportation and still in use today, making it one of the oldest railroad bridges still in service.

Relay, Maryland, or Relay House, Maryland, was formerly an important junction and rail stop on the Baltimore and Ohio Railroad, located 9 miles (14 km) west of Baltimore, Maryland. It was the busiest station on the line except for Baltimore itself. A town grew up around it: a general store, a school, and a volunteer fire company. Although the neighborhood is still inhabited, only the ghost of the town survives. There is no longer town government, a post office, nor are there any stores. The former fire house, at 1710 Arlington Avenue, at one point the town hall, has survived and is available for rental for events. In 2021 Relay is a historic district of Halethorpe, Maryland, near the intersection of today's Viaduct and Railroad Avenues. There is a Relay Elementary School.

The Lawn, is a historic home located at Elkridge, Howard County, Maryland, USA. It is a 19th-century frame house built in 1835 with five outbuildings, three of which (two cottages and a barn) date from the 19th century. The house was owned by George Washington Dobbin, who built the home originally as a summer retreat. The Rouse Company commercial corridor and road is named after Dobbin.It was listed on the National Register of Historic Places in 1984.In 2006, The Lawn was purchased after it had been apartments for many years. Many improvements were made, such as the library room floors being raised and refinished. In 2006, The Lawn was the Howard County Decorator Show house; professional decorators came in and refinished, furnished and decorated several rooms. Both the main kitchen and the butler pantry received renovations including new cabinets and appliances. The house was restored to its original glory.

Elkridge is an unincorporated community and census-designated place (CDP) in Howard County, Maryland, United States. The population was 15,593 at the 2010 census. Founded early in the 18th century, Elkridge is adjacent to two other counties, Anne Arundel and Baltimore.

First Baptist Church of Elkridge, is a historic African American Church located at 5795 Paradise Ave in Elkridge, Maryland. The building was constructed in 1877.

St. Denis station is a passenger rail station on the MARC Camden Line in the Maryland town of the same name. While the small station is the line's closest station to its terminus at Camden Yards in Baltimore, it has low ridership. St. Denis station contains two platforms and three tracks. The southbound platform, located on the corner of Arlington and Maple Avenues, has a shelter that is made of plexiglas and aluminum. MARC gives this platform as the official address of the station. The northbound platform contains a wooden shelter on an embankment at the end of East Street with the name of the station on the back of it. The station also contains two at-grade wooden pedestrian crossings, one which spans the entire right-of-way from Arlington Avenue to East Street, and the other which only runs from the southbound platform on Maple Avenue to the middle tracks. East of St. Denis, the Camden Line crosses over the MARC Penn Line south of the Halethorpe MARC station. The station itself, is an excellent spot for railfanning due to its proximity to Baltimore and its location at a point that sees Capital Subdivision, Baltimore Terminal Subdivision, and Old Main Line Subdivision freight traffic. A junction leading to the B&O Railroad Museum also exists between here and the terminus at Camden Yards.

The Elkridge Furnace Complex is a historic iron works located on approximately 16 acres (6.5 ha) at Elkridge, Howard County, Maryland.

The Lawyers Hill Historic District is a national historic district located at Elkridge, Howard County, Maryland. The district encompasses a broad array of architectural styles ranging from 1738 Georgian Colonial to 1941 Georgian Revival. The collection of Victorian domestic architecture built during the 1840s to 1880s is unparalleled in the county, with no two houses the same. Some of the later cottages were designed by Philadelphia architect Brognard Okie. There are variations of the American Gothic Revival form, Italianate, Queen Anne, and Shingle-style structures. There is also a range of Colonial Revival houses, from craftsman era rustic cottages to more formal Georgian, and mass-produced Dutch Colonial models from the early 20th century.The area developed originally in the 19th century as a summer community and early commuter suburb for prominent Baltimoreans. With the opening of the Thomas Viaduct in 1836, the Patapsco Valley south of the river was easily accessible to Baltimoreans. Many of the first residents were respected lawyers and doctors active in many of the professional and cultural organizations still vital in the state today. During the 1840s, as railroad service improved, Lawyers Hill residents began commuting to Baltimore on a daily and weekly basis, establishing the community as the state's first railroad commuter suburb.It was listed on the National Register of Historic Places in 1993.

The Belmont Estate, now Belmont Manor and Historic Park, is a former plantation located at Elkridge, Howard County, Maryland, United States. Founded in the 1730s and known in the Colonial period as "Moore's Morning Choice", it was one of the earliest forced-labor farms in Howard County, Maryland. Its 1738 plantation house is one of the finest examples of Colonial Georgian architectural style in Maryland.From the late 17th century until 1962, the property was privately owned and associated with important personages from the late 17th century to the 20th century, including Dr. Mordecai Moore, Caleb Dorsey, Alexander Contee Hanson, and David K. E. Bruce.The property was then successively owned and maintained as the Belmont Conference Center, by the Smithsonian Institution, the American Chemical Society, and Howard Community College. It is now the 68-acre Belmont Manor and Historic Park, owned by Howard County and its Department of Recreation and Parks. It adjoins Patapsco Valley State Park. Facilities on the estate include the Belmont Manor House, a carriage house, a cottage, a large barn, formal gardens, a pond, and an aqua garden.It is listed on the Maryland Historic Trust (MHT), Inventory of Historic Properties (MIHP), and is on the National Register of Historic Places (NRHP) as part of the Lawyers Hill Historic District, Elkridge, Maryland.

Deep Run is an 11.9-mile-long (19.2 km) tributary of the Patapsco River in central Maryland in the United States. The main stem arises in the vicinity of Ellicott City, starting in the Montgomery Meadows housing development, and the lower course forms part of the border between Howard and Anne Arundel Counties. It passes underneath Route 100 twice, Interstate 95 once, and Route 1 once as well. Archeological digs in 1929 discovered arrowheads, spearpoints, axes, and gorgets along the Disney farm. The banks of the Deep Run were a regular hiding place for slaves travelling north with the assistance of Harriet Tubman. The area was rezoned by the Howard County Department of Planning and Zoning to be unpreserved for historical status and is now occupied by commercial buildings along Hi Tech drive and Oxford Square development.

Herbert Run is a .413-mile-long (0.665 km) stream that flows through Baltimore County. It is a tributary of the Patapsco River, which flows into the Chesapeake Bay. Herbert Run divides into two tributaries, East Branch Herbert Run and West Branch Herbert Run, to the north. The headwaters of the East Branch are located near the Banneker Community Center in the neighborhood of Catonsville. The headwaters of the West Branch are located near Spring Grove Hospital Center in Catonsville.

Halethorpe station is a passenger rail station located in the unincorporated community of Halethorpe, Maryland on the Northeast Corridor. MARC Penn Line trains serve the station; Amtrak trains pass through but do not stop.Halethorpe station is located along Southwestern Boulevard (US 1) beneath a bridge for Francis Avenue, which also contains a staircase leading between the station and the bridge. A long parking lot between US 1 and the railroad tracks spans from north of the Washington Boulevard interchange to south of Tom Day Boulevard. South of Halethorpe, the Penn Line crosses under the MARC Camden Line east of the St. Denis station. The vicinity is considered an excellent spot for railfanning due to its proximity to Baltimore and its location at a point that sees CSX Capital Subdivision, Baltimore Terminal Subdivision, and Old Main Line Subdivision freight traffic.The station serves the University of Maryland Baltimore County two miles away. UMBC's Halethorpe/Satellite Transit Line provides a bus connection from the campus to the station. Additional communities include Arbutus, Catonsville, and Violetville.